Medical Aid in Dying (MAiD), i.e. active termination of life at a patient’s request, can confront physicians, patients and their families with substantial challenges and demands. Given its ethical contentiousness, MAiD remains a heavily debated medical and societal issue and concerns about developments in MAiD practice persist. While the impact of MAiD on the patient’s relatives is a major concern, little attention has been paid to the experiences of relatives. This proposal aims to gain a thorough understanding of grief, health consequences and bereavement care needs and provision among relatives of people with cancer who died by MAiD. To determine the impact of MAiD on bereaved relatives, I aim to study 1) grief and health consequences and 2) bereavement care needs and provision among relatives of people with cancer who died by MAiD. To achieve this goal, I will first conduct a prospective cohort study in which relatives of persons who died by MAiD (exposure group) are matched to relatives of persons who died without MAiD (control group). Secondly, I will qualitatively explore the experiences of relatives of persons who died by MAiD. This project will provide substantial insights into the impact of MAiD on bereaved relatives, how they cope, and the type and quality of care that is provided. As such, the findings of this project will dramatically advance our knowledge and understanding of the processes and consequences of MAiD practice.