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Medical Malpractice
Lawyers in Ontario

Ontario's health care system serves over 15 million residents, and the vast majority receive competent care. But when a health care provider's negligence causes harm, you have the right to hold them accountable. The team at Diamond and Diamond has offices across Ontario and experience handling medical malpractice claims throughout the province.

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Ontario Medical Malpractice

Harmed by Medical Care in Ontario? We Can Help.

We place enormous trust in the people who care for our health. Most of the time that trust is well placed. But when a health care provider's care falls below the standard a patient is entitled to expect, and that failure causes harm, the consequences can be life-changing.

Not every bad outcome is medical malpractice. Medicine involves risk, and even careful treatment can have disappointing results. A claim depends on showing that the care fell below the accepted standard and that this failure caused the harm. Sorting out whether that happened takes careful review and medical evidence.

The team of lawyers at Diamond and Diamond have experience handling medical malpractice claims across Ontario. Call our 24/7 injury hotline or fill out the form for a free case evaluation.

Past results are not necessarily indicative of future results and the amount recovered and other litigation outcomes will vary according to the facts in individual cases.

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Our Ontario Presence

Offices Across Ontario

With eight offices province-wide, experienced legal help is close to home no matter where in Ontario your injury occurred.

Head Office

Toronto

1920 Yonge Street, Suite 200

Ottawa

Serving Ottawa and Eastern Ontario

Barrie

Serving Barrie and Simcoe County

Kitchener

Serving Kitchener-Waterloo and the Region

London

Serving London and Southwestern Ontario

Sudbury

Serving Sudbury and Northern Ontario

Timmins

Serving Timmins and Northeastern Ontario

Windsor

Serving Windsor, Tecumseh and Essex County

Standard of Care

Medical Malpractice Law in Ontario

Medical malpractice in Ontario occurs when a health care provider delivers care that falls below the standard a reasonably competent practitioner in the same field would have met under similar circumstances, and that failure causes harm to the patient. The standard of care is measured against what a careful professional would have done, not against a perfect outcome.

Two things generally must be shown. First, that the care fell below the accepted standard. Second, that this failure caused the injury, rather than the underlying condition or an accepted risk of treatment. This second point (called causation) is often the most contested part of a claim, and it usually requires supporting medical evidence.

Ontario physicians are regulated by the College of Physicians and Surgeons of Ontario (CPSO), which sets standards for medical practice in the province. When negligence is suspected, acting quickly to preserve evidence and seek legal advice is critical.

Ontario standard of care in medical malpractice claims
Common Claims in Ontario

Types of Medical Malpractice Cases We Handle

Medical negligence can arise across every part of Ontario's health care system. Common examples include misdiagnosis or delayed diagnosis that allows a condition to worsen, surgical errors, medication errors, and preventable birth injuries. Others include errors in emergency departments, a failure to obtain informed consent before a procedure, and infections acquired in a health care setting that were not appropriately prevented or managed.

Ontario's health care system operates through a network of hospitals, community health centres, and private practices funded primarily through the Ontario Health Insurance Plan (OHIP). Whether your care was delivered at a teaching hospital in Toronto, a regional hospital in Sudbury, or a clinic in Windsor, the standard of care applies equally.

Each type of claim raises its own medical and legal questions. What matters is whether the care met the standard the patient was entitled to expect, and whether a failure caused harm.

Common medical malpractice claims in Ontario
Protect Your Claim
Request copies of your complete medical records as soon as possible. These are central to any review and will help your legal team assess whether the standard of care was met.
- Diamond & Diamond Lawyers
Why Experienced Representation Matters

Facing the CMPA in Ontario

When a medical malpractice claim is filed in Ontario, the physician is typically represented by the Canadian Medical Protective Association (CMPA), a mutual defence organisation with significant legal and financial resources. The CMPA has decades of experience defending physicians and access to medical and legal resources that can be difficult for an individual to match without strong legal representation.

This is one of the key reasons medical malpractice cases require a legal team with the experience, resources, and persistence to build a thorough case. The team at Diamond and Diamond understands how the CMPA defence process works and can help ensure your rights are protected throughout the proceedings.

In addition to claims against individual physicians, you may also file a claim against a hospital or health care institution if their policies, procedures, or staffing decisions contributed to your injury.

Common medical malpractice claims in Ontario

Harmed by Medical Care in Ontario? Call Us Today.

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Compensation

Damages in an Ontario Medical Negligence Claim

Depending on the circumstances, compensation in an Ontario medical malpractice case may include the cost of further medical treatment and care, lost income and reduced earning capacity, future care needs, out-of-pocket expenses, and damages for pain and suffering. Where negligence causes a lasting disability, the future portion of a claim is often the most significant.

Every claim is different, and its value depends on the medical evidence and how the harm affects a person's life over time. An early review helps you understand whether there is a claim and what it may involve.

The team of lawyers at Diamond and Diamond have experience handling medical malpractice claims and can help you understand the full scope of your potential compensation.

Damages in an Ontario medical negligence claim
Ontario Medical Malpractice

Areas of Focus

Our personal injury lawyers have experience handling a wide range of medical malpractice claims. Select an area to learn more.

Birth Injury

Claims involving injuries during birth, including cerebral palsy and brachial plexus injury.

Brain Injury

Concussions, traumatic brain injuries and long-term neurological damage from medical error.

Pediatric Injury

Medical mistakes affecting children, from misdiagnosis to treatment errors.

Misdiagnosis & Delayed Diagnosis

Missed or delayed diagnoses that led to worsened conditions or lost treatment windows.

Nursing Errors

Errors in medication administration, monitoring and basic care by nursing staff.

Medication Errors

Wrong medication, dosage mistakes, and interactions caused by prescribing or dispensing errors.

Surgical Errors

Wrong-site surgery, retained instruments, and other operative mistakes.

Fertility Medical Negligence

Claims arising from IVF, embryo handling, and other reproductive care errors.

Emergency Room Errors

Failures in triage, diagnosis, or immediate treatment in emergency settings.

Anesthesia Errors

Complications and injuries resulting from anesthesia administration or monitoring.

Hospital-Acquired Infections

Infections contracted during hospital stays due to lapses in care or hygiene.

Failure to Obtain Informed Consent

Procedures performed without proper disclosure of risks or without valid consent.

Hypoxic-Ischemic Encephalopathy (HIE)

A brain injury from oxygen loss around birth or during an acute medical event, and a leading cause of cerebral palsy.

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Frequently Asked Questions

A claim depends on showing that the care fell below the accepted standard and that this failure caused harm. Because that requires medical review, the safest first step is to have your records assessed rather than assume one way or the other. The team at Diamond and Diamond can arrange this review during a free consultation.

No. Medicine involves risk, and even careful treatment can have poor results. A claim requires showing that the care fell below the standard a reasonably competent provider would have met, and that this failure caused the harm. Not every bad outcome means negligence occurred.

The College of Physicians and Surgeons of Ontario (CPSO) is the regulatory body that licences and governs physicians in Ontario. While you can file a complaint with the CPSO, that process is separate from a civil lawsuit for damages. A personal injury lawyer can help you understand which path is appropriate for your situation.

The Canadian Medical Protective Association (CMPA) provides legal defence and liability protection to physicians across Canada, including Ontario. When a malpractice claim is filed, the CMPA typically represents the physician with significant resources. This is why having experienced legal representation on your side is essential.

Depending on the facts, a claim may involve a hospital, its staff, or other providers, in addition to a physician. In Ontario, hospitals can be held liable for the actions of their employees and for systemic failures in their policies or procedures. A personal injury lawyer at Diamond and Diamond can help identify all liable parties.

As soon as possible. There are important legal deadlines that apply to medical malpractice claims in Ontario, and evidence is easiest to gather early. A free consultation helps you understand your options before those deadlines pass. Call 1-800-567-HURT to get started.

Request your complete medical records, write down the timeline of your care while it is fresh in your memory, consider a second medical opinion to understand what happened, keep track of expenses and the impact on your work and daily life, and avoid discussing the situation with the health care providers involved. Most importantly, get legal advice early so no deadline is missed.

More Practice Areas

Explore more relevant practice areas and case types.

Birth Injury → Brain Injury → Catastrophic Injuries → Long Term Disability → Spinal Cord Injury → Car Accidents →

This page provides general information about Ontario law and is not legal advice. Every situation is different. For advice about your circumstances, speak with a lawyer.

Head Offices

Ontario Head Office

255 Consumers Road, 5th Floor, Toronto, Ontario

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Alberta Head Office

4246 97 Street NW, Unit 103, Edmonton, Alberta

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British Columbia Head Office

1727 West Broadway, Suite 400, Vancouver, British Columbia

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Main Offices

Barrie

Main Office

168 Bayfield Street

Calgary

Main Office

1331 Macleod Trail SE, Suite 645

Edmonton

Head Office

4246 97 Street NW, Unit 103

Halifax

Main Office

800 Windmill Rd Suite 301

Kitchener

Main Office

288 Frederick St

London

Main Office

256 Pall Mall St, Suite 102

Ottawa

Main Office

955 Green Valley Crescent, Unit 315

Sudbury

Main Office

31 Larch Street, Unit 300

Timmins

Main Office

120 Cedar Street South, Unit 002A

Toronto

Head Office

255 Consumers Road, 5th Floor

Vancouver

Head Office

1727 West Broadway, Suite 400

Windsor

Main Office

13158 Tecumseh Rd. E. Unit 3B

Additional Areas Served

Ontario

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British Columbia

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