Background: To describe the lessons learned after 10 years of use of the International Physical Activity Questionnaire (IPAQ) in Brazil and Colombia, with special emphasis on recommendations for future research in Latin America using this instrument. Methods: We present an analytical commentary, based on data from a review of the Latin American literature, as well as expert consultation and the authors' experience in administering IPAQ to over 43,000 individuals in Brazil and Colombia between 1998 and 2008. Results: Validation studies in Latin America suggest that the IPAQ has high reliability and moderate criteria validity in comparison with accelerometers. Cognitive interviews suggested that the occupational and housework sections of the long IPAQ lead to confusion among respondents, and there is evidence that these sections generate overestimated scores of physical activity. Because the short IPAQ considers the 4 physical activity domains altogether, people tend to provide inaccurate answers to it as well. Conclusions: Use of the leisure-time and transport sections of the long IPAQ is recommended for surveillance and studies aimed at documenting physical activity levels in Latin America. Use of the short IPAQ should be avoided, except for maintaining consistency in surveillance when it has already been used at baseline.