Background: Pharmacovigilance activities have been ongoing for 4 decades. However, little is known (especially outside of the area) about the contribution of Latin America to this field. Objective: To review and quantify the published literature on pharmacovigilance in Latin American countries. Data Sources: We searched electronic databases including MEDLINE (1966–2004), EMBASE (1980–2004), International Pharmaceutical Abstracts (1970–2004), Toxline (1992–2004), Literatura Latino-Americana e do Caribe em Ciências da Saúde (1982–2004), Sistema de Información Esencial en Terapéutica y Salud (1980–2004), and the Pan American Health Organization Web site (1970–2004) for articles on pharmacovigilance or adverse drug reactions in any of the 19 major Latin American countries. Papers were retrieved and categorized according to content and country of origin by 2 independent reviewers. Study Selection and Data Extraction: There were 195 usable articles from 13 countries. Data Synthesis: Fifty-one of the papers retrieved dealt with pharmacovigilance centers (15 national centers, 10 hospitals, 26 other), 55 covered pharmacovigilance itself (21 theoretical papers, 9 with description of models, 25 educational papers), and 89 were pharmacoepidemiologic studies of adverse drug reactions (69 case reports, 13 observational cohorts, 2 cohort studies, 1 randomized clinical trial, 4 clinical papers on adverse reaction management). Studies have increased exponentially since 1980. Five countries (Argentina, Brazil, Chile, Costa Rica, Venezuela) published reports from national centers. No studies were found from 6 countries: Dominican Republic, El Salvador, Honduras, Nicaragua, Paraguay, or Uruguay. Most studied categories were antiinfectives and drugs affecting the central nervous system, cardiovascular system, and musculoskeletal system. Conclusions: Contributions of Latin American countries to the field of pharmacovigilence have been remarkable, considering the constraints on these countries. A need exists for an increased number of formal pharmacovigilance studies and research using methodologically stronger pharmacoepidemiologic models.