Background: The authors investigated the outcome predictors in obese patients who underwent laparoscopic adjustable banding with the Lap-Band®. Methods:The 3-year excess weight loss (EWL) and rate of band-related complications (pouch dilatation and port leackage) were analyzed in 260 morbidly obese patients, according to several possible predictive characteristics. Success rate (EWL >50%), failure rate (EWL < 20%) and weight regain rate (regain of >10%EWL between 1 and 3 yrs) were considered. Results: The Lap-Band® produced a 43.0±22.3% EWL, corresponding to a BMI reduction from 46.6±7.0 to 36.8±6.6 kg/m2. Success rate was 35.7%, failure rate was 14.1% and weight regain rate was 20.7%. Pouch dilatation occurred in 32 patients (12.3%), band erosion in 2 (0.8%), port leakage in 74 (28.5%), and port twisting in 2 (0.8%). Major band-related surgery was requested in 11 patients (4.2%) and minor port-related surgery in 62 patients (23.9%). Significant success predictors were found to be age 2. Significant failure predictors were found to be male sex and non-sweet eating behavior. Significant weight regain predictors were found to be BMI 2 and the occurrence of a port leakage. Port leakage was significantly more frequent in women and in patients with BMI 2. The prevalence of pouch dilatation was threefold higher in women than in men. Conclusions: Lap-Band® was associated with a good outcome and with a low rate of severe complications. The outcome was more influenced by physiological and technical reasons than by psychological or behavioural factors.