Abstract Background Success after bariatric surgery should also reflect improvement in psychosocial functioning. The objective of this study was to assess the relationships between both mental health and eating disorders and weight loss in morbidly obese patients 2 years after gastric bypass. Methods Forty-three obese women (mean age, 39.3 ± 1.4 years; mean body mass index, 44.7 ± 0.4 kg/m2 ) were evaluated before and 1 and 2 years after gastric bypass. The Beck Depression Inventory and the Hospital Anxiety and Depression Scale were used for depression and anxiety evaluation and the Eating Disorder Inventory for eating disorder assessment. Results Decreases in depression ( P <.01), anxiety ( P <.05), and eating disorder ( P <.01) scores were measured 2 years after surgery. Both excess weight loss and change in body mass index were associated with improvements in all measured psychologic outcomes 2 years after surgery. Conclusions The importance of weight loss is in relation to mental health 2 years after bariatric surgery. Psychologic outcomes and eating disorders did not predict weight loss 2 years after gastric bypass. However, these factors improved significantly after weight loss.