The South Africa Stress and Health Study (SASH) is a large psychiatric epidemiological survey that is currently underway in South Africa. It is a part of the World Health Organization's World Mental Health (WMH) 2000 initiative and seeks to complete interviews with a nationally representative sample of 5000 adults. The WMH initiative is obtaining population-based data on the prevalence and severity of specific psychiatric disorders, demographic and psychosocial correlates of these diagnoses, and the levels and adequacy of mental health service utilization. SASH is using the fully structured pencil and paper version of the WHO Composite International Diagnostic Interview (CIDI) to assess lifetime and 12-month rates of mental disorders using both the DSM-IV and the ICD-10 diagnostic systems. In addition, the SASH seeks to collect information on the prevalence of exposure to physical and psychological torture in South Africa and to assess the association between such traumas and specific psychiatric disorders. It will also assess a broad range of risk factors and resources that may modify the association between exposure to human rights violations and mental health.