This paper reports on a five year follow-up of 174 morbidly obese patients (132 women) with gastric banding performed between 1981 and 1985. Mean preoperative weight was 122.6 +/- 1.4 kg (s.e.m.) (body mass index (BMI) = 41.8 +/- 0.4 kg/m2) and mean overweight was 73.2 +/- 1.6%. After rapid weight loss during the first six months weight levelled off reaching a nadir at 12-18 months. At 12 months mean weight loss was 36.5 +/- 1.2 kg (BMI = 29.1 +/- 0.4 kg/m2). At 60 months BMI had increased to 32.3 +/- 0.6 kg/m2 (P < 0.05 vs. 12 and 24 months). Mean excess weight at 60 months was 33.5 +/- 2.4% with 47.5% of patients maintaining less than 30% overweight. There were no differences in relative weight loss between men and women and no differences between stomal diameter of 12 or 15 mm 60 months after the operation. Early post-operative complications occurred in 25 patients (14.4%), four of whom required reoperation. Three of these re-operations were for perforations, one of which was fatal. Forty-eight patients (28%) had altogether 60 late complications requiring 26 reoperations (14.9%). There has been a total of four deaths (one clearly unrelated, one unknown) in the series. We conclude that gastric banding is a simple and safe gastric restrictive operation that is effective in about 50% of patients weighing between 90-181 kg (BMI 33-69 kg/m2).