What Evidence Will I Need for my Personal Injury Lawsuit?



February 4 2026

Good evidence is the backbone of every legal case, and a necessary ingredient for a court to be able to perform its task of deciding whether to grant a plaintiff’s claim. To advance your personal injury claim, there are several types of evidence that your lawyer will work with you to collect to advance your insurance claim, or in preparation for mediation or trial.

What is “evidence”?

Evidence is information used to prove facts; a fact is something that we know to be true. When you are in a lawsuit, you are going to make allegations about facts and circumstances to establish what happened to you and the injuries you sustained.

For example, your statement of claim might allege that the defendant rear-ended you and that this accident is the cause of your ongoing neck and back pain. Those allegations assert facts whose truth you will need to back up by placing compelling evidence before the court. The stronger the evidence, the harder it is for the other party to refute your claim.

What does the evidence have to prove?

To be successful, you will need to provide evidence about two key issues: liability (who is at fault) and quantum (losses related to your injuries).

Evidence about liability seeks to prove not only that the defendant’s conduct was wrongful, but also that it caused your injuries. Even if the defendant did something wrong, they will not be liable to you if their conduct was not the thing that caused you to sustain loss or injury.

Quantum is the dollar value of the losses that you have suffered. Quantum evidence must concretely establish what your injuries and damages are, as well as their financial cost to you.

Types of evidence

Building a successful case to support your claim will likely require several types of evidence.

Testimony

One of the most important types of evidence is live eyewitness testimony. Reliable eyewitnesses giving a firsthand account of what they know or saw can be extremely helpful to proving your case. The eyewitness may eventually be called to testify in court, where the information they provide will be sworn under oath, and the other side will have the opportunity to cross-examine them. However, your lawyer will want to speak to them well in advance of any court date in order to evaluate what evidence they have to offer and how it may help (or hurt) your case.

People who may be in a position to provide useful testimony could include yourself, your friends and family, witnesses to the accident, first responders or healthcare providers who can provide information about your injuries and subsequent rehabilitation progress.

Documentary or physical evidence

Important information about your claim will also come from documentary evidence. This type of evidence can include materials such as medical and employment records, tax returns, accident reports, emails, pictures, text messages, and video recordings. Every case will have thousands of pages of documentary evidence that will need to be considered by your lawyer.

In addition to records related to your injuries and losses after the accident, documents about your medical and employment history from before your accident may also be relevant to help establish what your circumstances were like before you were injured. How far back the records will need to go will depend on the circumstances of each particular case and an analysis of what is relevant and material.

Although documents like medical records are normally confidential, the filing of a personal injury lawsuit will require relevant and material records to be disclosed to the opposing party and their counsel. You will be required to sign a release allowing your lawyer to obtain copies of records that are relevant to your claim from your doctors and other treating professionals such as chiropractors and physiotherapists. That information will also be provided to the

Expert evidence

Once the documentary evidence about your medical condition and your employment history has been collected, it may be necessary to have an expert review that material and prepare a report that will help the court to interpret what the evidence proves.

Experts may be anyone who has knowledge (often gained through specialized education and experience) that is considered to be outside the common knowledge of the judge. In personal injury cases, it is typical to use medical experts to help the court assess the extent of your injuries and their relationship to the accident. If you are seeking compensation for loss of income – especially loss extending into the future – your lawyer may recommend using an economist or actuary to help calculate the value of those losses. We discuss the role of these and other types of experts in more detail in our previous post “5 Experts Your Personal Injury Lawyer Should Know About”.

You may also be asked to undergo an Independent Medical Examination or a Defence Medical Examination to assess and verify the extent of your injuries. This is standard in most personal injury cases. The additional information (evidence) gained from these examinations is helpful to narrow the issues and allows your lawyer to focus on the key issues in dispute. For more information about these examinations, you may find it helpful to review these posts:

An experienced injury lawyer should explain these processes to you and let you know what to expect.

Things to be mindful of

It is good to keep in mind that at the same time that you are working to collect evidence needed to advance your claim, parties adverse in interest to you are doing the same – for example, the insurance adjuster or counsel for the defendant(s). They will be interested in any information that might suggest your injuries are not as severe as you claim or otherwise contradicts your evidence about what occurred. There are practical things you can do to make sure you do not undermine your own case.

Accuracy, consistency and honesty are key

One is to make sure any information about your condition that you report to medical professionals or anyone you consult about your injuries is accurate and honest. Taking this approach fosters your credibility, and as we have discussed in previous posts, can significantly influence how an insurance adjuster, mediator, or (if necessary) a court may view your claim. See: “Credibility” and “Video Surveillance” for a more detailed discussion of the role credibility plays in building a strong case.

Be wary of posting on social media

A second item to be mindful of is what you post on your social media accounts after an injury and during your recovery. While it may feel natural to post about your accident, health, or state of mind following your accident, remember that other parties may be in a position to access that information and anything you or your contacts post could become evidence working against you at trial. In our view, staying off  social media while pursuing your personal injury claim is wise – see our post “Why You Should Stay off Social Media After You Are Injured in an Accident” for more information.

Contact us for help

If you have been injured in an accident and have questions about what kind of evidence you will need to prove your claim, CONTACT the lawyers at CAM LLP for a free legal consultation. Our experienced personal injury lawyers can help you get you the compensation you deserve.