Building on the 2000-01 WHO Multi-Country Survey Study, the World Health Surveys (WHS) were launched by the World Health Organization to strengthen national capacity to monitor critical health outcomes and health systems through the fielding of a valid, reliable, and comparable household survey instrument. The WHS was implemented between 2002 and 2004 in countries selected to represent all regions of the world. Study samples were nationally representative and probabilistically selected. Sampling weights were generated and adjusted for the population distribution with final post-stratification corrections for non-response. The total sample size, using nationally representative samples, includes over 300,000 individuals aged 18+ years. For six countries, China, Ghana, India, Mexico, Russia and South Africa, WHS also serves as SAGE Wave 0. Household data includes a household roster, health insurance coverage, health expenditures, and indicators of permanent income or wealth. Individual level data include sociodemographic information, health state descriptions, health state valuation, risk factors, chronic conditions, mortality, health care utilization, health systems responsiveness and social capital.