The literature suggests that bipolar elders with early and late onset of the disorder present with different demographic, family history, and psychosocial profiles, which are less well characterized than those for elderly unipolar patients. In this cross-sectional clinical survey, we assessed subjects (n = 74) from the NIMH Clinical Research Center for the Study of Depression in Later Life at Duke University who had a consensus diagnosis of bipolar depression; the primary assessment instrument was the Duke Depression Evaluation Schedule. We found that bipolar subjects with later age of onset reported less family history of psychiatric problems, more comorbid vascular disease, and more instrumental and subjective social support. Stressful life events were more frequent among bipolar subjects with earlier age of depressive symptom onset. This study suggests that early-onset disorder may be characterized by a psychosocial component, whereas organic factors may be particularly important to late-onset bipolar disorder.