The effect of treatment setting on success in a 16-week multidisciplinary cognitive-behavioral weight-management program was examined. Twenty-seven women and six men with an average initial weight of 198.13 lb (+/-39.10) participated in the program at a medical university (MU), their primary care physician's office (PCP), or their work site (WS). The average amount of weight lost, body mass index (BMI) decrement, and number of sessions attended were compared as measures of success between programs. Results supported the hypothesis that treatment setting affects program success [F(6,40)=0.54, P<.05]. WS was more effective than PCP [Wilk's lambda=0.59, P<.05] in promoting weight loss [F(1,2)=5.22, P<.05]. Results indicate that the ongoing contingencies in the WS environment promote weight loss through more consistent adherence to suggested weight-loss strategies.