The financial costs of community-based treatment, stressing home treatment, were compared with the cost of hospital-based treatment during one year. Of 155 patients destined to receive inpatient treatment, 76 were randomly assigned to home treatment, 79 to hospital treatment; the two groups were similar as to important social, demographic, and clinical characteristics. The principal differences between the two treatments concerned the focus of treatment, the locale of treatment, the degree to which continuity of treatment was maintained, and the roles of the respective treatment staffs. Manpower and operating costs, measured in dollars, were estimated in two ways. Either way, hospital-based treatment was more expensive during the year: 64.1% more expensive (+3,250 vs. +1,980 per patient) in the first instance, 108.9% more expensive (+6,750 vs. +3,230 per patient) in the second. With two exceptions during the first month of treatment, the proportions of patients and families receiving either treatment who incurred other costs of treatment were low, and the differences between groups were not significantly different. A higher proportion of patients and families receiving home-based treatment defrayed the cost of the patient's psychotropic drugs; second, a higher proportion of families of patients receiving hospital-based treatment defrayed transportation costs. The proportions of patients and families incurring costs of the consequences of illness were low, and the differences between treatment groups were not significant. We compared this study with similar studies, discussed the generalizability of the results of this study and similar studies, and identified issues for future research.