We investigated the possible differences in the utilization of psychiatric hospital beds among five social security areas in Finland, and the association between the variables related to the psychiatric services and the use of hospital beds. The use of hospital beds varied quite distinctly among these areas, as did the total rate of in-patients, readmissions, and rates of in-patients with psychotic and affective disorders. The treatment practices appeared to vary as the length of stay (LOS) and the rate of committal differed regionally in a significant manner. There was a significant positive correlation between the total rate of in-patients and the rate of readmitted patients (r=0.92, P<0.001), and a significant negative correlation between the number of visits per worker in out-patient care and the rate of readmissions (r=-0.94, P<0.001).