The results of a winter 1990 nationwide mail survey of pharmaceutical services provided in state psychiatric hospitals are reported and discussed. The survey universe consisted of all 207 state psychiatric hospitals registered by the American Hospital Association. Private and federal and other government-operated psychiatric hospitals were not included. Questionnaires were mailed to the director of pharmacy at each institution. Two questionnaires were not deliverable. There were 117 usable replies, for a net response rate of 57.1%. Compared with community hospitals, state psychiatric hospitals had pharmacy departments that were open fewer hours per week, occupied more floor space, were less likely to have a complete unit dose distribution system and i.v. admixture program, had lower inventory turnover rates, and had fewer full-time positions. About 28% of the respondents employed pharmacists who spent at least two thirds of their time providing clinical services. Differences in the provision of pharmaceutical services between state psychiatric hospitals and community hospitals may be due in part to the fact that most of the former are long-term-care institutions rendering a specific class of therapies.