As the prevalence of childhood obesity increases, exercise testing of obese children is likely to increase as well. This article discusses the implications of pediatric obesity for exercise testing and provides some recommendations for conducting tests and evaluating results. Studies comparing obese and nonobese children during exercise testing indicate that obese children are capable of meeting the challenges of exercise testing to nearly the same extent as their nonobese peers. Their physiologic responses, at least for the levels of obesity reported in the literature, are not sufficiently different from their nonobese counterparts to necessitate major changes in test protocols. Laboratory staff should pay special attention to fostering confidence in the obese child during the pretest routine.