We report on a 70-year-old man with severe respiratory failure caused by obesity hypoventilation syndrome due to abdominal adiposis. Obesity hypoventilation syndrome is a severe condition that is diagnosed when all of the following criteria are satisfied: body-mass index >30 kg! m 2 ; apnea hypopnea index >30; PaCO2 >45 mm Hg (in the daytime); and marked daytime somnolence. Abdominoplasty, which is generally used for abdominal laxness, striae, and rectus muscle diastases and for women in the postpartum period, was performed for this patient to facilitate ventilator weaning and produced a satisfactory result. (J Nippon Med Sch 2015; 82: 39 42)