Secondhand smoke (SHS) contains toxicants and carcinogens that are known to cause premature death and disease. Objectively measuring SHS exposure can support and evaluate smoke-free legislation. In Latin America, the most commonly used methods to measure SHS exposure are airborne nicotine and respirable suspended particles (PM₂.₅). Here we present results from studies conducted in public places and homes across Latin American countries. Airborne nicotine was detected in most locations between 2002-2006, before the implementation of 100% smoke-free legislation in Uruguay, Panama, Guatemala and other large cities within Latin America. Between 2006 and 2008, PM₂.₅ levels were found to be five times higher in places where smoking was present at the time of sampling compared to those without smoking. Measuring SHS exposure across Latin America has increased our understanding of the magnitude of exposure in this region and results have been used to effectively promote smoke-free legislation.