BACKGROUND Since 1983 gastric banding has become a proven operative method, which reduces effectively excess weight in morbid obesity. Gastric banding has been popularized as a minimally invasive, completely reversible surgical treatment for morbid obesity. We report here our 4 year experiences of gastric banding with special reference to complications. METHODS There were 109 patients in total, of whom 92 were women. Median age was 41.5 years (range 17-62 years) and median body-mass-index (BMI) was 49.6 kg/m2 (range 36.7-82.6 kg/m2). From February 1995 to June 1997 39 patients were operated upon with the open technique. In June 1997 we started the laparoscopic gastric banding. 70 patients were treated with this method from June 1997 to February 1999. RESULTS The weight loss 6 months postoperatively after gastric banding was 35.3% and 12 months after the operation 43.0% of the overweight. In 17 cases a re-operation was necessary. Indications for re-operations included pouch dilatation in 4 cases, slippage in 3 cases and complications connected with the port system. The operation technique and the kind of band fixation influenced the frequency of complications. CONCLUSIONS A lot of complications especially after laparoscopic gastric banding can be prevented by a strong indication. Using the laparoscopic technique complications like pouch dilatation are diminished compared to the open technique. A standardized operation technique decreases the complication and re-operation rate. Conversions to the open technique were mostly necessary during the learning curve of LASGB (laparoscopic adjustable silicone gastric banding).