Radon gas is a pulmonary carcinogen and the second leading cause of lung cancer after smoking. There are many countries that have not implemented measures to reduce the risk it poses to the general population. The aim of this study was to locate available evidence on exposure to residential radon and the regulations to monitor and control this across Central and South America, by conducting a review of the scientific literature and government documents in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review included 31 studies which had taken measurements of radon in these countries. While Brazil, Argentina, and Peru have undertaken most research, no country in Central and South America has a national map of exposure to residential radon. The prevalence of exposure to radon was uneven, both among the different countries and within individual countries. No country has regulations to prevent the entry of radon into homes, and nine countries have not set maximum permissible concentrations for residential radon. There is a limited number of studies in South and Central America, with a limited spatial coverage, and there is a need to improve knowledge on exposure to residential radon and its effects, and for governments to take the necessary actions to introduce preventive measures in their statutory regulations.