Objective - To investigate the rate of DSM-IIIR main affective disorders in a sample (52) of elderly medical patients consecutively admitted to a geriatric ward; to look for risk factors associated with depression; to compare the rate of depression with the one detected in community controls (117 subjects). Design - All consecutive patients admitted during January-February 1990 were assessed with a standardized psychiatric interview (Geriatric Mental State Examination) and with the Mini-Mental State Examination. Setting - The IV Geriatric Division (ward and day-hospital), Ospedale Civile Maggiore of Verona, which cares for elderly affected by medical illnesses. Main outcome measures - Depression was diagnosed according to the main DSM-IIIR categories for mood disorders. Results - Overall, an affective disorder was diagnose in 25% of the subjects (major depression 5,7%, dysthymic disorder 3,8%, n.o.s. depression 13,4%, adjustment disorder with depressive mood 1,9%). This rate was significantly higher when compared with the prevalence detected in community controls (25% vs. 11,1%). Older age, female sex, physical disability and distressing events were not associated with affective illness, while the lack of social support was significantly associated with depression. Conclusions - Elderly medical patients turned out to be an high risk group for depression, which deserves psychiatric screening and specific treatment.