The aim of the study was to estimate the prevalence of major depression and to evaluate associated features in random age cohorts of 75, 80, and 85 years (N = 651). A clinical examination was made by experienced health center physicians, and major depression was diagnosed according to DSM-III criteria. The prevalence increased with age and was 1% to 4% in the age groups of 75 and 80 years, but 13% at the age of 85 years. No sex difference was found. The frequency of major depression was fourfold among institutionalized patients (16%) as compared to those living at home (4%). Major depression was strongly associated with objective health, intellectual functioning, and functional capacity. Depression was most common in subjects suffering from poor vision, urinary incontinence, or Parkinson's disease (odd ratios 4.2 to 4.9). Depression was also correlated with musculoskeletal disorders, coronary heart disease, and cerebrovascular diseases (odd ratios 2.5 to 3.4). The survey suggests that major depression is quite rare in healthy elderly people but common in disabled institutionalized patients.