Best Medical Malpractice Lawyers in Ontario (2026)

The Limitations Act, 2002 generally allows two years to start an Ontario medical malpractice claim once you've discovered it.

The clock doesn't necessarily start when you receive treatment. Discovery depends on when you knew, or reasonably ought to have known, about the injury and how the health care provider's conduct was connected. Whether you could appropriately seek a remedy through a lawsuit matters as well.

Get help checking the dates early. An Ontario lawyer can explain how the limitation rules apply to your care; this guide gives general information, not legal advice.

When Ontario's limitation clock starts

The basic deadline comes from Sections 4 and 5 of the Limitations Act, which also set the discovery rules. The test looks at when you knew, or reasonably ought to have known, that you were hurt and that a provider's act or omission caused or contributed to the injury. The test also asks when you knew suing was appropriate.

Unless you prove otherwise, the Act treats the day of the act or omission as when you discovered the claim. A later discovery date needs evidence to support it. When you speak to your lawyer, give the treatment date, then say when you learned it might have contributed to your injury.

The outer limit is a separate clock

Section 15 sets the ultimate limitation period running from the act or omission, not from when you discover it. When the link between medical care and your injury takes much longer to become clear, that outer limit may matter. You don't get more time under the ordinary discovery deadline because of this outer limit.

Minors without a litigation guardian qualify for exceptions, which also cover incapacity. There's also wilful concealment. Tell your lawyer if you think someone deliberately hid information about your care; they'll need to check whether you qualify for an exception. The deadline doesn't change just because you believe that.

Claims involving children

The basic limitation period doesn't run for a patient under 18 (a minor) who has no litigation guardian for the claim. Neither condition's optional. A child's age alone won't tell you their deadline.

The ultimate period stops running too if the claimant is a minor without a litigation guardian when the claim arises. Borden Ladner Gervais LLP explains this rule in its article on Wong v. Lui, 2023 ONCA 272, which you can read here. An Ontario lawyer can explain what a litigation guardian's involvement means for the child.

What Ontario's damages cap actually limits

The rules depend on what you've lost. There's no statutory cap on economic losses, such as lost income or future care. Pain and suffering, along with loss of enjoyment of life, are non-pecuniary damages covered by the national, judge-made cap.

The Supreme Court of Canada's trilogy, including Andrews v. Grand & Toy Alberta Ltd., set the non-pecuniary limit. The amount rises with inflation. McKellar Structured Settlements publishes indexed figures if you need the amounts (McCague Borlack LLP discusses the trilogy cap and indexation).

Don't read the cap as a typical award. Although the cap doesn't limit economic losses, courts reserve the full amount for the most catastrophic injuries. Ask your lawyer to keep proposed future-care costs out of the amount sought for pain and suffering when you discuss a possible claim.

What you need before and at filing

Ontario lets you start malpractice claims against hospitals, or doctors and nurses, without pre-suit notice. Starting a claim doesn't require you to get an affidavit or certificate of merit, either. Even without those filing requirements, you'll still need medical evidence.

To prove the standard of care and causation, you'll need expert evidence from a physician working in the same field. Their evidence answers different questions: what care was expected, then whether the provider's conduct caused or contributed to your injury. Ask whether the proposed medical review will address both questions separately.

You must serve expert reports by the deadlines in the provincial court rules. The reports fall under Rule 53.03 of Ontario's Rules of Civil Procedure. Even though no filing certificate is required, you can't put off the medical review; have a lawyer check the report deadlines that apply.

If the provider says you share fault

A patient's own negligence doesn't bar a claim under Ontario's Negligence Act, though it does reduce damages. Fault gets divided. If the defence says you did or didn't do something, tell your lawyer openly so they can assess how it might affect your claim.

Most physicians in Canada have the Canadian Medical Protective Association defending them; it contests most claims. Because claims are contested, seek early legal advice and medical evidence. If a claim is contested, that alone isn't a finding that your account is wrong.

How a case generally moves forward

Your case won't follow a timetable set by this general outline. Ask your lawyer what you'll need to do before filing and how Ontario's court rules govern the next steps.

What you can do now

Describe what happened; include dates. When you write your account, separate what happened during treatment from what you learned later, especially any explanation linking the injury to a provider's act or omission.

• Mark the entries you'd like checked in the medical records you already have, then set them aside for your lawyer.
• Your notes need the date you first suspected a link between the injury and the care. Include what happened that made you think the two were connected.
• You'll need care costs and lost-income information to discuss those economic losses on their own, apart from pain and suffering.
• The lawyer needs to know whether a litigation guardian has been involved when you're claiming for a child. The child's age alone won't give you the deadline.

You don't have to sort out the legal questions before asking for help. Bring any questions you have about missing records or the discovery date to your consultation with the lawyer.

Find an Ontario lawyer

How does the lawyer review your medical care and work out the limitation period? You can browse our lists for lawyers in Toronto, Ottawa, Hamilton or London. Look for a consultation where you can talk through your care and the dates, not just hear a general explanation of malpractice law.