OBJECTIVE: This study aimed to investigate the prevalence of depression in aged spouse pairs and the associations between the occurrence of depression in one spouse (respondent) and the variables representing the respondent himself/herself and his/her partner. METHOD: Elderly (65 years or older) male (N = 176) and female (N = 176) spouses who constituted married couples that had participated in the epidemiological study on depression in old age conducted in Ahtäri, Finland, in 1989-1990 made up the study series. The data were collected by postal questionnaires, interviews, and clinical investigations. Depression was determined according to the DSM-III criteria. RESULTS: Both husband and wife were depressed in 5.7% of the married couples. The husband was depressed and the wife was nondepressed in 10.2% of the couples; and the wife was depressed and the husband nondepressed in 10.8% of the couples. Among male respondents, poor physical health of the respondent, poor marital or family relations felt by the respondent, poor family relations felt by the marital partner, and a loss of the father by the marital partner while the partner was under 20 years of age were independently related to depression. Lowered functional abilities of the respondent was the only factor independently associated with the occurrence of depression in female respondents. CONCLUSIONS: The coexistence of depression in both elderly spouses is not uncommon. The results also give some evidence to suggest that the vulnerability for the development of depression in the wives may have some effects on the development of depression in elderly men.