BACKGROUND AND STUDY AIMS: To determine long-term outcome after treatment with an intragastric balloon for 6 months, with no structured weight maintenance program offered after balloon removal. PATIENTS AND METHODS: 100 consecutive overweight/obese individuals (mean body mass index [BMI] 35.0 +/- 5.6 kg/m (2)) were prospectively followed after endoscopic implantation of a saline-filled intragastric balloon; 97 completed final follow-up at a mean of 4.8 +/- 1.6 years. Successful intragastric balloon therapy was defined as weight loss at 6 months of ≥ 10 % of weight at baseline, that remained ≥ 10 % until 2.5 years, without bariatric surgery. All analyses followed intention-to-treat principles. RESULTS: At 6 months, mean weight loss was 12.6 +/- 8.3 kg, 63 individuals had ≥ 10 % baseline weight loss; no severe morbidity was detected. During the first and second years following intragastric balloon removal, mean body mass increased by 4.2 +/- 6.8 and 2.3 +/- 6.0 kg, respectively ( P < 0.001 for both year-on-year comparisons). At 2.5 years, intragastric balloon therapy had been successful in 24 participants. At final follow-up (4.8 +/- 1.6 years), 28 had ≥ 10 % baseline weight loss, 35 had undergone bariatric surgery (60 % had preoperative mass higher than baseline), and 3 were lost to follow-up; the 34 remaining had lost 1.5 +/- 5.8 kg compared with baseline. During follow-up, 13 had a second intragastric balloon implanted and 13 took sibutramine for short periods. CONCLUSION: Intragastric balloon therapy was relatively innocuous and associated with successful weight loss and maintenance at 2.5 years in a quarter of participants. It represents a valid option for weight loss.