This study focuses on mental health problems and compares the association of demographic and socioeconomic factors to the use of mental health specialty care and general medical care in the United States and the Canadian province, Ontario. It also examines how lack of insurance coverage in the United States and perceived need for care affects differences between the two countries. We employ a cross-sectional study design using the 1990 U.S. National Comorbidity Survey and the 1990 Mental Health Supplement to the Ontario Health Survey. Overall, 8.8% of Americans report one or more visits to the health sector for a mental health problem, compared to 6.9% of Canadians in Ontario. Americans with the highest incomes and no mental morbidity are much more likely to receive services than their Canadian counterparts. By contrast, Americans with the lowest incomes and high morbidity are much less likely to receive services for mental health problems than a similar group of Canadians. These results suggest that universal and comprehensive coverage, as exists in Ontario, does not necessarily lead to increased use of services with low value. However, the greater prevalence of perceived need for care among Americans with higher socioeconomic status and low mental morbidity suggests that the United States should be cautious in drawing lessons from other countries.