OBJECTIVES Across countries with varying political, socioeconomic and cultural environments, we sought to identify predictors of generic drug utilization. METHODS Data were collected from national and international regulatory agencies, MEDLINE and internet searches for 37 countries classified as “advanced” or “emerging” economies by the International Monetary Fund: Argentina, Australia, Austria, Belgium, Brazil, Canada, China, Cyprus, Denmark, Finland, France, Germany, Greece, Iceland, India, Ireland, Israel, Italy, Japan, Luxembourg, Malta, Mexico, Netherlands, New Zealand, Norway, Portugal, Russia, San Marino, Singapore, Slovenia, South Korea, Spain, Sweden, Switzerland, Taiwan, United Kingdom, United States. We compared the presence of generic policies, first year of generic legislation, branded drug patent duration, proportion of generic drug utilization, and pricing for generics (government control, free market, or other), gross domestic product, and population across countries. Only independent variables with p<0.20 in univariate regression were included in the multivariate model: population, year of generic legislation, patent life, and pricing for generics (market vs. government control). RESULTS Of 37 countries, data was available for 26 (70%): Argentina, Australia, Austria, Brazil, Belgium, Canada, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Japan, Mexico, Netherlands, New Zealand, Norway, Portugal, Russia, Singapore, Spain, Sweden, Switzerland, United Kingdom and United States. Most countries enacted generic drug legislation in the 1990s, 9 (35%) introduced legislation before 1990, and 3 (12%) after 2000. Branded drug patent duration was 15-20 years for 65% of countries. Among countries with generic drug laws, only free market-based generic pricing, compared to government-controlled pricing, was associated with a nominal increase in generic drug utilization (B=0.17, 95% CI -0.01, 0.35). CONCLUSIONS Countries with free market pricing policies had minimally greater diffusion of generic drugs compared to countries with government pricing controls. Further investigation of other characteristics, namely the political and social climates that foster greater generic drug utilization is planned.