In an epidemiological survey of the prevalence of mental illness in homeless individuals in Munich, Germany, a probability sample of 32 homeless women were interviewed using a standardized diagnostic instrument (Diagnostic Interview Schedule for DSM-III diagnoses). Results point to very high prevalence rates of mental disorders among homeless women. The most frequent diagnostic groups were alcohol and drug abuse (lifetime prevalence rate 90.6%), affective disorders (50.0%), anxiety disorders (43.8%) and schizophrenia (21.9%). Prevalence rates are compared with a female household sample (Epidemiological Catchment Area Study in New Haven, Connecticut). All disorders tended to be more frequent in homeless women as compared with the household sample. Our results show the urgent need to provide medical and other assistance to homeless women. There is a need for adequate psychiatric care, supply with food and housing and the development of concepts for personal and vocational rehabilitation considering the specific needs of women.