OBJECTIVE The authors' goal was to study the importance of different psychiatric disorders in relation to suicide in individuals 65 years old or older. METHODS The psychological autopsy approach was used to study 85 cases of suicide among subjects who were 65 years old or older; 153 living comparison subjects from the same age group who were randomly selected from the tax register were interviewed face-to-face. Retrospective axis I diagnoses were made according to DSM-IV on the basis of interview data and medical records. RESULTS Ninety-seven percent of the suicide victims fulfilled criteria for at least one DSM-IV axis I diagnosis, compared with 18% of the living comparison subjects. Recurrent major depressive disorder was a very strong risk factor for suicide, as was substance use disorder. An elevated risk was also associated with minor depressive disorder, dysthymic disorder, psychotic disorder, single-episode major depressive disorder, and anxiety disorder. Comorbid axis I disorders were observed in 15 (38%) of the 39 elderly subjects with major depressive disorder who had committed suicide. CONCLUSIONS Although recurrent major depressive disorder was the mental disorder most strongly associated with suicide, the findings of this study suggest that elderly individuals who commit suicide represent a heterogeneous group with regard to mental disorders, implying a need for differentiated prevention strategies.