BACKGROUND The purpose of this analysis was to examine: (1) the prevalence of psychiatric disorders among disabled people, using seven different measures of disability; (2) variation in disability between and within psychiatric diagnostic categories; and (3) relationship of diagnosis and disability to health service utilization. METHODS Data were drawn from Phase I and Phase II of the Eastern Baltimore Mental Health Survey, part of the Epidemiologic Catchment Area Program (ECA) conducted in 1980-1 to survey mental morbidity within the adult population. A total of 810 individuals received both a household interview and a standardized clinical psychiatric evaluation. Estimated prevalence rates were computed using appropriate survey sampling weights. RESULTS Prevalence of disability ranged from 2.5 to 19.5%, varying with specific disability measure. Among those classified as disabled by any of the measures examined, 56 to 92% had a psychiatric disorder and serious chronic medical conditions were present in the majority of these cases (54 to 78%). Disability was expressed differently among the various diagnostic groups. Diagnostic category and disability were significant independent predictors of medical service utilization and receipt of disability payments. CONCLUSIONS The majority of disabled adults living in the community have diagnosable psychiatric disorders, with the majority of these individuals suffering from significant chronic medical conditions as well, thus making co-morbidity the norm.