Objective: To better understand the strengths and weaknesses of systems of services for seriously mentally ill individuals in Canada and the United States, the quality and cost of services in the province of British Columbia (population 3.2 million) were compared with those of services in the 50 states. Methods: A survey of selected psychiatric facilities, data from the Canadian Ministry of Health, and information from families and consumers were assessed using methods similar to those used in a 1990 survey that rated services for individuals with serious mental illness in the 50 states. Separate scores were given for hospitals, out-patient and community support services, rehabilitation services, housing, and children's services. Results: British Columbia scored higher than any single state in the United States and more than twice as high as 40 states on the quality of services for seriously mentally ill individuals, Compared with the states, British Columbia ranked ninth in cost of services per capita. When ratings of quality and cost were combined, British Columbia appeared to be delivering services almost twice as good as those in New York State at about half the cost. However, recent trends, such as shortages of inpatient beds and increasing numbers of seriously mentally ill persons among the homeless population, suggest that British Columbia's services may be deteriorating. Conclusions: Probable reasons for the superior services for seriously mentally ill individuals in British Columbia include single-source funding, a strong mandate to treat such individuals, and a comprehensive approach to providing services. The Canadian health system, as implemented in British Columbia, has definite advantages for individuals with serious mental illnesses.