Hypertension is a major health risk factor in patients who are morbidly obese. Two hundred eighty-nine morbidly obese patients undergoing gastric restrictive surgery were evaluated for the presence of hypertension (blood pressure greater than or equal to 160/90 mm Hg or currently undergoing antihypertensive therapy) pre- and postoperatively. Of 74 (26%) preoperatively hypertensive patients, 67 (91%) were available for follow-up. Preoperative hypertension resolved in 66% (44 of 67) of patients following gastric restrictive surgery. Superobese and morbidly obese patients had similar reductions in hypertension after surgery (69% versus 63%). Patients not receiving antihypertensives preoperatively had a greater reduction of hypertension than those medically treated preoperatively (78% versus 58%). The amount of weight loss significantly predicted the reduction of hypertension, whereas follow-up weight achieved did not. The amounts of weight loss for patients with resolved and persistent hypertension were 89.3 +/- 5.6 lbs (mean +/- standard error of the mean +ADSEM+BD) and 66.0 +/- 8.3 lbs, respectively (p less than 0.02). For patients with resolved hypertension, follow-up weights for the morbidly obese and superobese were 162.0 +/- 10.8 lbs (133% +/- 4% ideal body weight +ADIBW+BD) and 220.4 +/- 9.5 lbs (170% +/- 7% IBW). Gastric restrictive surgery is effective therapy for hypertension in morbidly obese patients. Patients need not achieve weights approaching IBW to enjoy the benefits of gastric restrictive surgery on hypertension.