We evaluated 77 consecutive patients who had undergone horizontal gastroplasty over a 2 year period. Mean follow-up was 26 months (88 percent of patients) and ranged from 15 to 45 months. There were no operative deaths. Early complications were common. Stomal dilatation resulting in cessation of weight loss or in weight regain occurred in 19 patients (25 percent). Stomal stenosis occurred in four patients. Among patients with an intact gastroplasty, the percentage excess weight decreased from a preoperative mean of 142 +/- 46 percent to 80 +/- 38 percent at 1 year, 68 +/- 30 percent at 2 years, and 83 +/- 45 percent at 3 years. Fewer than 25 percent of the patients weighed less than 50 percent above ideal body weight at 2 or 3 years. In our experience, horizontal gastroplasty was associated with an unacceptably high mechanical failure rate. Using strict criteria, weight loss was generally inadequate at 2 years and not sustained, even in patients with intact gastroplasty.