We introduced intragastric balloon placement in Japan and evaluated the initial data. Between December 2004 and March 2008, intragastric balloons [BioEntericsA (R) Intragastric Balloon (BIBA (R)) system] were placed in 21 Japanese patients with obesity [six women, 15 men; mean age 40 A +/- 9 years; mean body mass index (BMI) 40 A +/- 9 kg/m(2)]. The inclusion criteria were morbid obesity (BMI a parts per thousand yenaEuro parts per thousand 35 kg/m(2)), the presence of obesity-related disorders, and failure with conventional treatments for at least 6 months. The balloon was routinely removed under endoscopy after 5 months. No serious complications occurred, but in two of the 21 patients (9.5%), early removal (within 1 week) of the balloon was required due to continuous abdominal discomfort. Two other patients (9.5%) could not control their eating behavior and were considered unresponsive to the treatment, and their balloons were also removed before 5 months. Seventeen of the 21 patients (81%) finished the treatment, and the average weight loss and percent excess weight loss (%EWL) at the time the balloons were removed were 12 +/- 5 kg and 27 +/- 9%, respectively. Eight patients were followed for 1 year without intervention of consecutive bariatric surgery, and at that time, four of these patients had kept more than 20% of %EWL. The other patients regained their weight in the first year. Intragastric balloon placement is a safe and effective procedure in obese Japanese patients, and about half of the patients will maintain their weight loss after the balloon is removed.