This study aimed to isolate psychological predictors of outcome from horizontal reinforced gastric surgery for morbid obesity. Fifty-seven patients were assessed pre-operatively and 1 year after surgery. Prior inpatient psychiatric history (but not outpatient history), MMPI scale elevations, negative life events, and low social support (predictors) related significantly to medical complications and satisfaction with results of surgery, but not weight loss (outcome). Prior inpatient psychiatric history and low social support also predicted psychological complications postoperatively. Demographic factors failed to predict any aspects of outcome. Multiple regression analyses of the four significant predictors explained 43 percent of the variance in medical complications, 42 percent in satisfaction, and 31 percent in psychological complications. Inpatient psychiatric history was the strongest single predictor in all cases.