To build this evidence-based 2026 list of misdiagnosis lawyers serving Vaughan, we looked at their practice focus and published results, plus client reviews and professional recognition.
Our featured firm in Vaughan is Diamond & Diamond Lawyers LLP, where Jeremy Syrtash leads the medical malpractice group. Among the firms we reviewed, Paul Cahill stands out because he focuses on medical negligence and has published trial results. Before you call, find out who would take on your diagnostic error claim and what fees and case costs you'd face. Whether you still have time to start it also depends on Ontario's limitation rules.
Jeremy Syrtash leads the medical malpractice litigation practice at Diamond & Diamond Lawyers LLP. He earned a BA from Yeshiva University (2010) and a JD from the University of Ottawa (2013), was called to the Bar of Ontario in 2014, and has acted as counsel and co-counsel in medical malpractice cases across Canada, many involving pediatric and obstetrical negligence.
Called to the Bar of Ontario, 2014 · JD, University of Ottawa · Best Lawyers: Ones to Watch in Canada, Health Care Law (2024 to 2027)
On Paul Cahill's site, you'll find an $11.5 million jury verdict for a child born with cerebral palsy, plus a successful trial against an emergency room physician after a mother's death. That's experience at trial. What your misdiagnosis claim might recover isn't answered by either.
Stood out in our review for the recognition it has earned and how much of its work is medical malpractice.
We order firms by how much of their work is medical malpractice, the results they publish, what their clients say, their experience, their standing with the regulator and the recognition they have earned, all from public records and the firms' own sites. How lists are made
Since its founding in 1935, Thomson Rogers LLP has built a long history of litigation. According to its site, a medical malpractice success survived an appeal in Denman v. Radovanovic, 2024 ONCA 276. If you're looking into misdiagnosis, the firm lists it among its case types and names lawyers Aleks Mladenovic and Sebastian di Domenico.
Stood out in our review for its years of experience and what its clients say.
We order firms by how much of their work is medical malpractice, the results they publish, what their clients say, their experience, their standing with the regulator and the recognition they have earned, all from public records and the firms' own sites. How lists are made
Not sure who to call first?
Tell us what happened. A malpractice lawyer who serves Vaughan can look at it with you, and it costs nothing.
Best for: Neurological and paediatric injury claims
Medical malpractice is central to Neinstein LLP's listed practice. When describing its work, the site names stroke, cerebral abscess and spinal infection, and also discusses paediatric injury. If you're worried that a missed diagnosis caused neurological harm, those details give your family something to ask about first.
Stood out in our review for how much of its work is medical malpractice and the recognition it has earned.
We order firms by how much of their work is medical malpractice, the results they publish, what their clients say, their experience, their standing with the regulator and the recognition they have earned, all from public records and the firms' own sites. How lists are made
When clients describe Bogoroch & Associates LLP, they repeatedly mention prompt replies and being kept informed. With 210 reviews behind the firm's 4.9 Google rating, those comments come from a substantial pool of reviewers. Follow-up was missed, says one person.
Stood out in our review for the recognition it has earned and what its clients say.
We order firms by how much of their work is medical malpractice, the results they publish, what their clients say, their experience, their standing with the regulator and the recognition they have earned, all from public records and the firms' own sites. How lists are made
When you explain the missed diagnosis, give the lawyer the date you learned you'd been harmed. Ontario's 2-year discovery rule makes those dates important to your deadline. Don't assume the clock started when you received treatment, because your lawyer needs to check when you discovered the claim under that rule.
Records and medical review
Your chart lets the lawyer check the care you received, then see what happened to you afterward. To assess the standard of care (the care expected), medical opinions consider whether your care met it, then examine whether the alleged error caused or contributed to injury, which is causation.
Starting the claim
If the applicable limitation period has expired, you can't start your claim. You don't need an affidavit or a certificate of merit to begin in Ontario. If the patient is a child without a litigation guardian for the claim, rules that pause the clock may give you a different deadline.
Expert reports
You'll have to serve expert reports on the standard of care and causation to meet Ontario's court rules. What medical evidence does your lawyer need, and who will pay to obtain it? Those questions about the care need more than proof of a missed diagnosis.
Resolution or trial
If your claim doesn't settle, it may go all the way to trial. How would your lawyer decide whether a proposed resolution was acceptable? You can read published verdicts to learn what happened in another person's file, not to work out what result you can expect in your own case.
Malpractice claims in Vaughan: the rules that matter
The filing deadline in Ontario
The clock startsWhen you found out, or should have
Time to start a claim2 yearsMiss it and the claim is usually lost.
At the very most15 yearsafter the treatment, with a few exceptions
Limits on damages in Ontario
Pain and sufferingCapped at about $484,330
All damages togetherNo overall cap
Expert paperworkNo affidavit or certificate of merit is required to start a claim.
A written agreementThe share the lawyer takes, set out before work starts.
If you recover moneyThe agreed share and the case costs come out of it.
If the claim failsNo legal fee on a contingency agreement. Ask about costs.
You can use contingency fees at several of the listed firms. If your claim fails, the lawyer gets no lawyer's fee; a recovery means they'll take a share of it. Records and medical opinions still cost money, and you'll have court fees to pay on top of those expenses. Who pays while the claim is underway, and who pays at the end, isn't explained in the firms' fee information. If the claim doesn't succeed, what expenses would you owe, and who covers them while it's underway? Before you sign anything, ask the lawyer to explain plainly how they'll calculate the fee and what the case costs. Even with a free consultation, you can't assume the whole claim will cost nothing.
Six of the eight listed firms offer a consultation you won't pay for; contingency fees are available at five.
What to bring to your first call
Your appointments written out in date order, with symptoms and diagnoses alongside
When you first learned of your injury and that the care might have been incorrect
Who provided your health care, with their names written down
Any medical charts you have copies of, plus your diagnostic reports and test results
Anything the hospital or an insurer sent you by letter or message
What you've paid in bills, with records of your lost income
Your injuries as shown in photos you've taken
If the patient is your child, their age and what you know about any litigation guardian for the claim
Questions to ask a lawyer
1Have you handled delayed diagnosis claims like mine, and how many?
2Who would take on my file once we've first spoken?
3How would you check whether the missed diagnosis was what caused my harm?
4How long is the limitation period for my claim?
5How do you work out the contingency fee?
6Would I owe money for medical opinions and records if my claim fails?
7How will you keep me updated, and how can I reach the lawyer?
8Where's our meeting place?
Choose around the missed diagnosis
Start with what worries you. Perhaps the diagnosis came late, a condition went undetected or treatment followed the wrong diagnosis. Ask whether the lawyer has handled that kind of claim. A birth injury verdict shows trial experience, but it doesn't tell you how that lawyer would assess your delayed diagnosis.
The work these firms take on isn't the same. While Neinstein LLP's listed practice centres on medical malpractice, several other firms include that work within a broader injury practice. Who worked on files like yours, and what did they involve? Even if recognition helps you draw up a shortlist, you still need to talk about those files.
Ask how the file would work
Before signing with the firm, ask who would assess your claim and whether that lawyer would remain involved afterward.
How would the firm obtain your chart and arrange medical opinions to determine whether the care fell short and caused harm?
How you'll receive updates needs agreement. Although several firms get positive comments about communication, some clients also complain about delays or follow-up that never happened.
Where would you meet? Since most listed offices are outside Vaughan, you may be meeting in Oakville or Windsor, not Toronto.
When a consultation is free, you can have an initial discussion about whether the firm might take your case without paying for it. That doesn't make later expenses free. If you agree to contingency fees, the lawyer receives part of any recovery but gets no fee when the claim fails. Ask what court fees you'll face before signing, then ask separately about the cost of records and medical opinions.
If someone promises a result or won't explain the fee agreement, be careful about hiring them. You can start an Ontario claim without first obtaining a certificate of merit. Since court rules require expert reports on the standard of care and causation, ask the firm how it will examine the medical evidence before taking your claim forward. Don't treat this page's general information as legal advice.
Questions people ask
How long do I have to start a misdiagnosis claim in Vaughan?
When you discover the claim, Ontario's basic limitation period of 2 years begins. You must know, or reasonably be expected to know, that you've been injured and that a provider's act or omission contributed to it, including whether bringing a lawsuit was appropriate. There's also a 15-year ultimate period under the Limitations Act. How those rules fit your dates is something to ask an Ontario lawyer.
Does every wrong diagnosis support a malpractice claim?
If you received a wrong diagnosis, that alone doesn't prove your care fell below the expected standard or answer whether the care caused you an injury. Both questions need answers before you proceed. You'll have to serve expert reports on the standard of care and causation under Ontario's court rules. What would your chart and medical opinions have to show for your lawyer to support the case?
Do I need a medical expert's certificate before starting?
To start a medical malpractice claim in Ontario, you don't need an affidavit or a certificate of merit. You'll still need medical evidence to meet the court rules requiring you to serve expert reports on the standard of care and causation. When you'll need those reports, and how you'd pay for them, are questions a lawyer can explain.
Can I speak to a lawyer without paying for the first meeting?
If you're seeking a free consultation, six listed firms say they offer one: Thomson Rogers LLP, Neinstein LLP, Bogoroch & Associates LLP, Howie, Sacks & Henry, Bergel Magence LLP and Diamond and Diamond Lawyers. What will we discuss then? Check, then book. You'll need to find out what fees and expenses pursuing the claim would involve, even when you don't pay for the first discussion.
What does a contingency fee mean for my family?
The lawyer's fee comes from a share of any recovery under this arrangement, so there's no lawyer's fee to pay when the claim fails. Five listed firms let you use this arrangement. Records and medical opinions aren't included in the lawyer's fee, and you'll also have court fees to cover. Who pays those expenses while the claim is underway, and would you owe them if it fails?
What deadline applies if the patient is a child?
The 2-year period doesn't run until someone turns 18 if they have no litigation guardian for the claim. If the claimant has no litigation guardian when the claim arises during childhood, the 15-year ultimate period also pauses, as addressed in Wong v. Lui, 2023 ONCA 272. Does that rule apply to this claim, and can an Ontario lawyer check it?
How long will a delayed diagnosis case take?
You won't find a fixed timetable for these claims. Before the claim can proceed, records and medical evidence need review, then expert reports must be served to meet the court rules. What does the firm still need to investigate, and how will it keep you informed as that work proceeds? Since some listed firms' clients have complained about delays, agree on updates before hiring and find out who will be responsible for your file.
Can I seek help if my loved one died after a missed diagnosis?
If your family needs help with a wrongful death claim, several listed firms discuss that work on their sites, including Thomson Rogers LLP and Bergel Magence LLP. After a mother's death, Paul Cahill reports winning a trial against the emergency room physician involved in her care. You can't tell from that result whether your family has a claim. After reviewing what happened to your loved one, an Ontario lawyer can explain which rules apply and how long your family has to start a claim.
Is there a limit on compensation in Ontario?
There's no statutory cap on economic losses, such as your lost income and future care costs. Your financial expenses aren't subject to the national judge-made trilogy cap, which limits non-pecuniary damages for things such as pain and suffering. Knowing which losses have a cap won't tell you what your claim might recover. Which losses could you claim in your circumstances is a question for an Ontario lawyer.
Do I need a lawyer with an office in Vaughan?
You'll find a Vaughan office listed for Singer Kwinter; the other firms list offices elsewhere, so don't assume those offices are in the city. If you're booking with a listed Oakville or Windsor office, check where it is before making arrangements. Who would handle your file, and where would you meet them? Once you've described the missed diagnosis that worries you, ask the lawyer about their experience handling claims where patients received that kind of incorrect care.
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Jeremy Syrtash
