Background: The use of the Bio-Enterics intra-gastric balloon (BIB) has been shown to be a safe and effective procedure for the temporary treatment of morbid obesity. We conducted a retrospective comparative analysis of the weight loss in patients that after BIB removal underwent bariatric surgery and those who did not wish surgery. Methods: From January 2000 to March 2004, 182 BIBs were positioned in 175 patients (104 F / 71 M; mean age 37.1±11.6 years, range 16-67; mean BMI 54.4 ± 8.1 kg/m2, range 39.8-79.5; mean %EW 160.8±32.9% range 89-264). Patients were excluded from this study who had emergency BIB removal for balloon rupture (n=2, 1.1%) and for psychological intolerance (n=7, 7.8%). All patients were scheduled for a bariatric operation, before BIB positioning. After BIB removal, a number of patients now declined surgery. Consequently, patients were allocated into 2 groups: Group A in whom BIB removal was followed by bariatric surgery (Lap-Band®, laparoscopic gastric bypass, duodenal switch) (n=86); Group B patients who after BIB removal refused any surgical procedure (n=82). Both groups were followed for a minimum of 12 months. Results were reported as mean BMI and %EWL ± SD. Statistical analysis was done by Student t-test or Fisher's exact test, with P<0.05 considered significant. Results: Mean BMI and mean %EWL in the 166 patients at time of removal were 47.3 ± 8.1 kg/m2 and 32.1±16.6%, respectively. At the same time, mean BMI was 47.6±6.9 and 48.1±6.5 kg/m2 in group A and B (P=NS). At 12 months follow-up (100%), mean BMI was 35.1 kg/m2 in Group A (BIB + surgery) and 51.7 kg/m2 in Group B (BIB alone) (P<0.001). Conclusions: After BIB removal, half (49.4%) of the patients scheduled for surgery refused a bariatric operation. These patients returned to their mean initial weight at 12 months follow-up. Therefore, bariatric surgery after BIB removal is highly recommended.