The current study assessed the efficacy of hypnosis as an adjunct to a standard cognitivebehavioral program for the treatment of obesity. Weight loss was compared among participants who received the standard cognitive-behavioral treatment (CBT), those who received hypnosis in addition to the standard cognitive-behavioral treatment (H-CBT), and a minimal treatment control group focusing on nutrition and exercise information (C). Treatment consisted of eight consecutive weekly group sessions of 1.5 hours and weight was recorded at the beginning of each session. A large effect size (d = .85) was found between H-CBT and C, a moderate effect size (d = .61) was found between CBT and C, and a small effect size (d = .28) was found between H-CBT and CBT. Thus, both the H-CBT group and the CBT group outperformed the minimal treatment group. A small effect size was found between H-CBT and CBT.