Patients with double-chambered right ventricle presenting with symptoms in adulthood are rare. From 1990 to 2004, 4 adults and 9 children with double-chambered right ventricle underwent surgical correction. The surgical results and clinical data of the adults were compared with those of the pediatric patients. All adult patients had dyspnea on exertion, 3 children showed growth delay but the others were asymptomatic. The mean age at operation was 44.5 +/- 6.3 years in adults and 5.2 +/- 1.9 years in children. The mean pressure gradient between the anatomically lower right ventricle and the pulmonary artery was significantly higher in adults than in children (91.8 +/- 14.1 vs. 42.2 +/- 5.9 mm Hg). The pulmonary-to-systemic flow ratio in adults was significantly lower than in pediatric patients (1.2 +/- 0.2 vs. 1.8 +/- 0.3). All adults and 8 of the 9 children survived. There were no late deaths or re-operations, and all survivors were in New York Heart Association functional class I. Surgical correction of double-chambered right ventricle in adults gave satisfactory midterm results although right ventricular outflow tract obstruction and clinical symptoms were severe in these patients.