In the Upper Bavarian Field Study a total of 1536 persons (15 years and older) were interviewed by research psychiatrists. The prevalence of diabetes (ICD 250) identified by the interviewer and/or the primary care physician was 4.0%. Since the number of diabetics among the younger age groups was relatively low (n = 7) and in order to obtain a more homogeneous study group, only those over the age of 55 were considered in further analysis. Diabetics were compared with a control group of persons with another chronic medical condition of similar clinical severity and a control group without a somatic disorder. The sex- and age-adjusted prevalence of psychiatric disorders identified with the aid of the Clinical Interview Schedule was significantly higher among diabetics (43.1%) and persons with other chronic medical conditions (50.7%) in comparison to the healthy control group (26.2%). The difference was mainly due to mild psychiatric disorders and those suffering from depression. No statistically significant association was found between diabetes and moderate to severe mental disorders, the use of psychotropic drugs and previous psychiatric treatment.