This study tested whether the efficacy of behavioral treatment of obesity (BT) might be improved through the use of a personalized system of skill acquisition (PSA) with reinforcement contingent on the mastery of changes in eating and exercise behaviors. A total of 108 obese adults were randomly assigned to one of three conditions: (1) BT + PSA; (2) BT; or (3) a weight-loss educational (WLE) program. At posttreatment, the BT + PSA and BT conditions demonstrated significant beneficial changes in caloric consumption, intake of fats, and level of physical activity. Both conditions also produced equivalent reductions in body weight (Ms = 7.9 kg for BT + PSA and 9.5 kg for BT) that were significantly greater than the reduction accomplished in the WLE condition (M = 1.7 kg). These findings suggest that the addition of a PSA may not produce better outcome than standard behavioral treatment and that education alone is not sufficient to produce weight loss.