Background: Vertical banded gastroplasty (VBG) and gastric bypass (GBP) are the two bariatric procedures recommended by NIH consensus conference. Recent advancement in laparoscopic (L) techniques has made LVBG and LGBP alternatives for the conventional open approach. Methods: From December 2000 to February 2002, 80 patients (24 men and 56 women; mean age 32 years, range 18-57) with morbid obesity (mean BMI 43.2 kg/m2, range 36-59.8) were enrolled in a prospective trial and randomly assigned to LVBG or LGBP. Changes in quality of life were assessed using the Gastro-intestinal quality of life index (GIQLI). Results: The conversion rate was zero for LVBG and 2.5% (1/40) for LGBP. There has been no mortality. Surgical time was significantly longer for LGBP (209 minvs 126 min for LVBG, PPPPPP<0.01). LVBG had improvement in physical condition, social function and emotional conditioning but deterioration in GI symptoms which resulted in no increase in total GIQLI score. Conclusion: LGBP was a time-consuming demanding technique with a higher early complication rate compared with LVBG. Although both operations resulted in significant weight reduction and decrease in obesity-related co-morbidities, LGBP had a trend of greater weight loss and significantly better GIQLI than LVBG at the cost of a significant long-term trace element deficiency state. Each patient should be individualized for the operations according to the patient's decision.