Twenty years since legalisation, euthanasia (defined as active termination of life at patient’s request) remains a highly controversial issue, especially concerning adults with psychiatric conditions (APC). Previous research has mostly focused on mapping practice and how legal eligibility criteria are implemented in APC, with little attention paid to the origins of requests. Moreover, existing models in suicidology do not seem readily applicable to requests for euthanasia. The purpose of this research is a comprehensive examination of factors and mechanisms at various socio-ecological levels that play a role in the development, formulation, and outcome of euthanasia requests in APC. By means of a mixed-method approach using quantitative and qualitative research, including interviews and focus groups, we aim to: (1) gain a deeper insight in the individual, social and socio-cultural factors associated with APC requesting euthanasia, and how they relate to outcomes of their euthanasia trajectory; (2) gain a deeper understanding of how the interplay of these factors influence ideas about a hastened death, and in the risk and protective factors surrounding death seeking behaviour; (3) map needs and expectations regarding culture-sensitive, inclusive mental health care, and possible courses of action to achieve this. Gaining this comprehensive picture of contextual factors will yield fundamental insights, further (inter)national debate, and impact on clinical assessment procedures.