When a minor research participant reaches the age of majority or the level of maturity necessary to be granted legal decision-making capacity, reconsent can be required for ongoing participation in research or use of health information and banked biological materials. Despite potential logistical concerns with implementation and ethical questions about the trade-offs between maximising respect for participant agency and facilitating research that may generate benefits, reconsent is the approach most consistent with both law and research ethics.Canadian common law consent requirements (...) are expansive and likely compel reconsent on obtaining capacity. Common law doctrine recognises that children are entitled to decision-making authority that reflects their evolving intelligence and understanding. Health consent legislation varies by province but generally either compels reconsent on obtaining capacity or delegates the ability to determine reconsent to research ethics boards. These boards largely rely on the Canada’s national ethics policy, the Tri-Council Policy Statement, which states that, with few exceptions, reconsent for continued participation is required when minors gain capacity that would allow them to consent to the research in which they participate. A strict interpretation of this policy could require researchers to perform frequent capacity assessments, potentially presenting feasibility concerns. In addition, Canadian policy and law are generally consistent with the core principles of key international ethical standards from the United Nations and elsewhere.In sum, reconsent of paediatric participants upon obtaining capacity should be explicit and informed in Canada, and should not be presumed from continued participation alone. (shrink)