This study investigated the physical activity and beliefs about exercise of 30 adolescents with diabetes. The Seven-Day Physical Activity Recall was used to determine the physical activity for two different recall periods that were 2-weeks apart. Forty percent of the youths engaged in 30 minutes of moderate activity 5 times per week while only 10% engaged in 20 minutes of vigorous activity 3 times per week. Forty-seven percent of the teens consistently achieved or surpassed the time equivalent of activity for one of the Healthy People 2000 Objectives for moderate or vigorous physical activity. This group had significantly higher scores on the Exercise Belief Instrument for Adolescents that was developed for this study. Strategies to encourage regular physical activity are discussed.