Our aim was to systematically identify and compare how generic medications, as defined by the US Food and Drug Administration (FDA), World Health Organization (WHO), and European Medicines Agency (EMA), are classified and defined by regulatory agencies around the world. We focused on emerging markets and selected the most populated countries in each of the WHO regions: Africa, the Americas, Eastern Mediterranean, Europe, Southeast Asia, and Western Pacific. A structured review of published literature was performed through December 2013. Direct information from regulatory agencies and Ministries of Health for each country was extracted. Additionally, key informant interviews were performed for validation. Of the 21 countries selected, approximately half provided an official country-level definition for generic pharmaceuticals. The others did not have any definition or referred to the WHO. Only two-thirds of the countries had specific requirements for generic pharmaceuticals, often associated with clinical interchangeability. Most countries with requirements mention bioequivalence, but few required bioavailability studies explicitly. Over 30 % of the countries had other terms associated with generics in their definitions and processes. In countries with generic drug policies, there is reference to patent and/or data protection during the drug registration process. Several countries do not mention good manufacturing practices as part of the evaluation process. Countries in Africa and Eastern Mediterranean regions appear to have a less developed regulatory framework. In summary, there is significant variability in the definition and classification of generic drugs in emerging markets. Standardization of the definitions is necessary to make international comparisons viable.