This chapter presents data on past-year mental health service use, and discusses the practical and methodological issues to be considered when developing a core set of questions about people's use of psychiatric services for use in psychiatric epidemiological surveys. It presents preliminary data on mental health service use from the first four countries that have contributed data on this topic to the International Consortium of Psychiatric Epidemiology (ICPE) master data bank. The chapter also illustrates the use of the multiple data sources by comparing use of any services for mental health problems in the 12 months prior to the survey. It is important to examine the utilization rates for mental health services across countries, adjusting for the presence of disorders. The cross-national comparisons offer over a reasonable basis to generate hypotheses about what accounts for similarities and differences in the rates of mental health service use between countries.