--- title: "Professional Malpractice and Negligence" date: 2026-10-12 author: "K&S" url: https://cohenmurisonlaw.com/personal-injury/professional-negligence/ --- ![](https://cohenmurisonlaw.com/wp-content/uploads/2026/10/negligence-hospital.webp) # Harmed by a professional's mistake? *The clock may have started when you found out.* We look at what went wrong, whether it fell below the standard expected of that professional, and whether it caused your loss. Then we tell you plainly if there's a claim. ## Thank you, we have it. We'll call you during office hours, 9 am to 5 pm, 7 days a week. If you think two years have nearly passed since you found out, call now. [Book a free video meeting now](https://calendar.app.google/p4UydfDQwFAi1NRUA) [Call (289) 309-3069](tel:+12893093069) Deadline check ## Two limits apply. *The earlier one wins.* The two years usually run from when you knew, or should have known, that you were harmed, that someone's act or omission caused it, who it was, and that a lawsuit is the right way to fix it. - 2 **years from when you discovered the claim** - 15 **years from the mistake itself, at the very most** Date of the treatment or advice Date you found out (optional) Enter the date of the treatment or advice to see your deadlines. [Get in touch](#review) General information, not legal advice. The law presumes you knew on the day of the mistake unless you can show otherwise. Different rules apply to children, people who couldn't start a claim because of their condition, and mistakes that were deliberately hidden. We'll confirm your deadline. Who it covers ## Medical malpractice *and other professionals.* The legal test is much the same for every profession. What changes is the evidence, the defence and how the loss is measured. Read the full guide: [Medical malpractice in Ontario: how to sue a doctor or hospital](/insights/medical-malpractice-ontario/). For patients and their families ### Medical malpractice - Missed or delayed diagnosis - Surgical and medication errors - Injuries during labour and birth - Treatment given without informed consent [Ask about medical care](#review) For clients who lost money or rights ### Other professionals - Lawyers who missed a deadline or gave wrong advice - Accountants whose errors led to tax or financial loss - Real estate agents who misrepresented a property - Other licensed professionals you relied on [Ask about a professional](#review) What you must prove ## A bad result *isn't enough on its own.* Professionals are judged on whether they acted reasonably at the time, not on perfection and not with hindsight. A claim needs all four of these. [Ask about your situation](#review) 1. **A duty of care**The professional owed you care, usually because you were their patient or client. 2. **A breach of the standard of care**They fell below what a *reasonable, prudent professional* of similar training and experience would have done in the same circumstances. 3. **Causation**Their mistake caused or contributed to your harm. If the same result would have happened anyway, there's usually no claim. 4. **A real loss**Injury, extra medical care, lost income, or money lost because of the advice or work. Expert opinion ## Why an independent opinion *comes first.* A court can't decide on its own what a reasonable surgeon, accountant or lawyer would have done. That evidence comes from an independent professional in the same field, who reviews the records and gives an opinion on the standard of care and on causation. Ontario's court rules set out what an expert's report must contain, and the expert must sign an acknowledgment that their duty is to give fair, objective and non-partisan evidence. They are not there to argue for either side. That's why we start by collecting the records and having them reviewed. If the opinion doesn't support a claim, you'll know before you take on a lawsuit. ### Claims against doctors Doctors in Canada can get legal help from the Canadian Medical Protective Association (CMPA), a not-for-profit mutual defence organization. It isn't an insurance company. It provides medico-legal help to physicians and also compensates patients harmed by negligent care. In practice, it means the doctor will have an organized, well-prepared defence, and your claim needs to be prepared just as carefully. Your options ## A complaint *or a lawsuit?* They do different things, and you can do both. Only one of them can pay you compensation. ### Complain to the regulator Each regulated profession has a body that investigates complaints, such as the College of Physicians and Surgeons of Ontario (CPSO) for doctors. A complaint can lead to discipline. The CPSO says it can't award financial damages. **Usually fits when**You want the conduct looked at and the professional held to account, whether or not you claim money. ### Sue for compensation A civil claim in court is how you recover your losses: income, care costs, pain and suffering, or the money the mistake cost you. It must be started within the limitation period. **Usually fits when**The mistake caused you real harm or financial loss and an independent opinion supports the claim. Your first meeting ## What to bring *to your meeting.* Bring what you have. You have a right to your own health records, and we can help you request anything missing. - **A timeline**What happened, when, and when you first suspected something was wrong. - **Records you already have**Hospital or clinic records, test results, or the professional's file. - **Names of everyone involved**Doctors, nurses, the hospital, or the firm and the person who did the work. - **Letters, emails and agreements**Retainers, engagement letters, consent forms and any advice in writing. - **Proof of your losses**Pay stubs, receipts, tax notices, or later bills to fix the problem. - **Any complaint you've made**And any reply from the regulator, the hospital or the firm. ★★★★★ > “His guidance was clear, honest, and very reassuring during a stressful time.” **S* Sana ChaudharyGoogle review* Videos ## Watch it *explained.* [More on YouTube](https://www.youtube.com/@CohenMurisonLaw) Questions ## Malpractice and *professional negligence* Don't see yours? Call [(289) 309-3069](tel:+12893093069). How long do I have to sue a doctor or other professional? Usually two years from when you discovered the claim, under Ontario's Limitations Act, 2002. The law presumes you knew on the day of the treatment or advice unless you can show otherwise. And no matter when you found out, you generally can't sue more than 15 years after the mistake. Different rules apply to children, to people who couldn't start a claim because of their condition, and where the mistake was deliberately hidden. I only found out about the mistake years later. Is it too late? Not necessarily. The two years usually start when you knew, or reasonably should have known, that you were harmed, that it was caused by someone's act or omission, who that was, and that a lawsuit was an appropriate way to fix it. But the 15-year ultimate limit still applies, so don't wait. Is a bad outcome the same as malpractice? No. Professionals are judged on whether they acted as a reasonable, prudent member of their profession with similar training and experience would have at the time, not on perfection or hindsight. You also have to show that their mistake caused your harm. Why do I need an expert opinion? A court needs evidence from an independent professional in the same field about what the standard of care was and whether the mistake caused your harm. That's why we gather your records and have them reviewed before a lawsuit goes far. Should I complain to the regulator or sue? They do different things, and you can do both. A complaint to a regulator, such as the CPSO for doctors, can lead to discipline, but the CPSO says it can't award financial damages. Compensation comes from a lawsuit, which must be started within the limitation period. How do legal fees work? Either a small amount upfront and the rest only if you're compensated, or no legal fees at all unless you're compensated. The fee is set out in a written contingency fee agreement, plus HST. The first video meeting is free. In-person meetings at First Canadian Place are $100. Related ## Other claims *we handle.* [**Long-Term Disability**Read more](https://cohenmurisonlaw.com/personal-injury/long-term-disability/) [**Slip and Falls**Read more](https://cohenmurisonlaw.com/personal-injury/slip-and-fall/) [**Dog Bites**Read more](https://cohenmurisonlaw.com/personal-injury/dog-bites/) [**Breach of Contract**Read more](https://cohenmurisonlaw.com/personal-injury/breach-of-contract/) Free video meeting ## Think something went wrong? *Find out where you stand.* By video (free) or in person at First Canadian Place ($100), 7 days a week. [Book a free video meeting](https://calendar.app.google/p4UydfDQwFAi1NRUA) [Call (289) 309-3069](tel:+12893093069) [Send a message](#review) **Cohen Murison Law** 100 King Street West, Suite 5700 First Canadian Place, Toronto, ON M5X 1C7 Open 7 days, 9 am to 5 pm. Closed on public holidays. --- ## Cohen Murison Law - Website: https://cohenmurisonlaw.com - Contact: pawan@konanandspade.com