Psychological autopsy is one of the most valuable tools of research on completed suicide. The method involves collecting all available information on the deceased via structured interviews of family members, relatives or friends as well as attending health care personnel. In addition, information is collected from available health care and psychiatric records, other documents, and forensic examination. Thus a psychological autopsy synthesizes the information from multiple informants and records. The early generation of psychological autopsies established that more than 90% of completed suicides have suffered from usually co-morbid mental disorders, most of them mood disorders and/or substance use disorders. Furthermore, they revealed the remarkable undertreatment of these mental disorders, often despite contact with psychiatric or other health care services. More recent psychological autopsy studies have mostly used case-control designs, thus having been better able to estimate the role of various risk factors for suicide. The future psychological autopsy studies may be more focused on interactions between risk factors or risk factor domains, focused on some specific suicide populations of major interest for suicide prevention, or combined psychological autopsy methodology with biological measurements.