Background The assessment of suicide risk is a complex task for mental health professionals. Certain demographic groups are associated with completed suicide including males, divorced adults, and Caucasians. However, demographic variables alone provide a crude assessment of suicide risk. Psychiatric diagnosis and recent life events might improve the identification of high-risk individuals. Method The current study evaluated 148 individuals who died by suicide compared with 257 adults who died suddenly from accidents or medical problems. Psychological autopsy was used to assess Axis I psychiatric diagnosis and recent stressful life events. Results: Suicide completers were significantly more likely than comparison subjects to have a depressive disorder, a substance abuse disorder, and to have experienced interpersonal conflict in the months leading up to their death. A discriminant function analysis revealed that the combination of demographic variables, recent stressful life events, and psychiatric diagnoses best discriminated between suicide completers and comparison subjects. Conclusions Proper assessment of suicide risk should include a comprehensive evaluation of demographic characteristics, recent life stressors, and psychiatric diagnosis.