Two thirds of Americans are overweight or obese. Traditional obesity interventions (e.g. drug therapy, diets, behavior therapy) generate moderate short-term weight loss but have little evidence of long-term weight maintenance. The cultural phenomenon of "yo-yo dieting" mirrors empirical findings which suggest that weight loss, albeit demanding, is a far easier process to target than weight maintenance. The present study sought to evaluate the efficacy of an acceptance based behavioral intervention designed to generate improvements in psychological health and quality of life in obese and overweight adults as well as encourage gradual and sustainable weight loss. The therapy package combined the traditional behavioral interventions of self-monitoring and goal setting with an Acceptance and Commitment Therapy (ACT) protocol across eight weekly individual therapy sessions. While no significant immediate weight loss was observed following the intervention, significant improvements in general psychological health, reductions in anxiety and escape maintained eating, and increases in weight related acceptance and action were found in the treatment group (n = 9) compared to a wait list control group (n = 10). These findings suggest that an acceptance based intervention targeting wide band outcomes might serve as a viable alternative to traditional approaches targeting only immediate weight loss.