The prevalence rates of mood disorders according to the DSM- III -R criteria in the community elderly were investigated with structured interviews conducted by psychiatrists. The subjects were 1,965 randomly selected residents aged 65 years or more who lived in Nagai City, Japan. In the first phase, a questionnaire including the short form of the Geriatric Depression Scale (GDS) was distributed to all subjects. In the second phase, all persons scoring 6 points or more on the GDS and approximately half as many of these persons randomly selected from the remaining respondents scoring 5 points or less were examined by psychiatrists using the A and D modules of the Structured Clinical Interview for DSM-III-R. The 1-month prevalence rates of major depression and bipolar disorder were estimated to be 0.9% and 0.0%, and the current prevalence of dysthymia was estimated to be 0.5%. By using additional unstructured clinical interviews, we also found the prevalence rates of adjustment disorder with depressed mood and other types of depression to be 3.8% and 2.5%. For these categories of depression, prevalence rates did not differ significantly by sex or age group, except that the prevalence of adjustment disorder with depressed mood was significantly higher in women than in men.