While recent psychosocial stress has been shown to be associated with the initiation of both first and subsequent illness episodes in bipolar affective disorder, its relationship to completed suicide in bipolar disorder is not known. As a part of a nationwide psychological autopsy study, two populations representing all suicides in Finland in DSM-III-R bipolar disorder or unipolar major depression were comprehensively examined and compared. Recent life events were retrospectively examined by interviewing next of kin using a 32-item Recent Life Change Questionnaire. Life event data was available on 25 bipolar and 56 unipolar cases. In about two-thirds of both bipolar (64%) and unipolar (66%) victims, at least one life event was reported to have occurred during the last 3 months and in 42% of both groups during the final week. The events of bipolar victims were more commonly classified as possibly dependent on their own behaviour (bipolars 88% vs. unipolars 63%, P = 0.004). Among bipolars, more males than females had had recent life events (males 86% vs. females 37%, P = 0.03). The majority of completed suicides in both bipolar and unipolar affective disorders seem to be associated with recent psychosocial stress; however, the stressors are commonly likely to be dependent on the victim's behaviour.