OBJECTIVES: To define the current processes and key decision makers involved in gaining market access in Brazil, Argentina, Mexico and Colombia, and identify opportunities and challenges to market access in these countries. METHODS: The websites of the appropriate authorities and agencies in each country and the Decision Resources Group’s ‘Global Market Access Solution’ database were reviewed. RESULTS: The healthcare systems in Brazil, Argentina and Mexico are decentralised, while that of Colombia is centrally managed. All countries have a national health service for all residents, but the proportion of the population that relies solely on this varies greatly between countries. In Brazil, 25% of the population has private health insurance, while only a small proportion of the population relies on private insurance in the other countries. In Mexico and Argentina, residents in formal employment are obliged to enrol in one of the social security sponsored schemes. In Brazil, Argentina and Colombia, national formularies include the mandatory minimum healthcare provision. In Mexico, the national formulary is not binding and the different social security schemes decide which treatments to cover. The role of health technology assessment (HTA) in the reimbursement process varies in different countries. In Brazil, Mexico and Colombia, HTA is critical in the reimbursement decision process, while in Argentina it has been mostly used to assess treatments for catastrophic illnesses; although there is a drive to include HTA in the decision process. Opportunities include a growing demand for pharmaceuticals, and challenges include decentralised healthcare systems and high use of generics. CONCLUSIONS: Most countries have a decentralised system where reimbursement decision making occurs at the regional level or at the social security funds level. HTA is critical in decision making in Brazil, Mexico and Colombia, but not yet in Argentina. We have identified current opportunities and challenges for the different countries.