Many jurisdictions in Canada have enacted legislation that requires physicians to report their patients to the Ministry of Transport if they have a medical condition that may put them at increased risk to operate a motor vehicle. The Canadian Cardiovascular Society has published guidelines that are designed to assist physicians and policy-makers in their decision-making. Legislation is designed to protect society, and the guidelines are designed to fulfill that mandate. However, in the present paper, important issues that have not been addressed to date are discussed. What is the efficacy of mandatory reporting legislation? What are the harms done to patients who are restricted from driving? What are the costs of the mandatory reporting system? How can the scientific/technical assessment of risk be reconciled with the social/ethical view of risk assessment? Until these issues are addressed, important questions about the ethics, efficacy and cost of mandatory physician reporting will remain unanswered.