The Duty to Mitigate

The duty to mitigate is an important legal concept in personal injury law, particularly with respect to quantum of damages considerations. But what is the duty to mitigate and what happens when an injured person fails to mitigate their losses?

What is the duty to mitigate?

Generally speaking, there is a principle in law that injured persons must take all reasonable steps to reduce the negative consequences of their injuries and to prevent the accumulation of losses. An injured person must facilitate their own recovery and take all reasonable steps towards minimizing their losses – whether those be physical, psychological, emotional or financial. This is known as the duty to mitigate.

While it is called the duty to mitigate, it is not, strictly speaking, a “duty” because the mere failure to mitigate is not actionable on its own. Rather, mitigation is a partial defence. A wrongdoer or Defendant may argue that while their negligence or other tortious conduct may have caused the injured person’s injuries, they should not be held fully responsible for the injured person’s losses if the injured person failed to mitigate. The legal onus is on the wrongdoer or Defendant to prove that the injured person failed to mitigate.

For example, in Janiak v Ippolito, 1985 SCC 62, the Court had to determine whether the injured person’s refusal to undergo a surgery to repair his spinal injury meant that he could not claim compensation from the Defendant for his financial losses as he was unable to work with his back injury. The onus was on the Defendant to prove that:

a) The plaintiff acted unreasonably in refusing to undergo the recommended treatment (surgery), AND

b) The extent to which the plaintiff’s damages would have been reduced had he acted reasonably.

What happens when an injured person fails to mitigate?

Where an injured person fails to mitigate their losses, courts have held that an injured person should not receive compensation from the wrongdoer for losses that they suffered to the extent that the injured person could have avoided the losses.  To put it another way, if it is held that there has been a failure to mitigate, the damages are reduced and are assessed as if there had been mitigation.


The information provided on this website does not constitute legal advice and should not be construed as such. Moustarah & Company does not guarantee that this information is accurate or up to date. As a result, should you require legal advice, please contact a lawyer.