A 40-year-old female was admitted to the hospital with the chief complaints of dyspnea on effort. Echocardiography and cardiac catheterization revealed an abnormal muscle bundle in the right ventricle which divided right ventricle into two chambers with the pressure gradient of 86 mmHg between them. And severe regurgitation associated with hypoplastic pulmonary valve and ventricular septal defect were noted. We removed the abnormal muscle bundle through the right atrial and ventricular approach, and pulmonary valve replacement and VSD closure were carried out. We report a case of two-chambered right ventricle with severe pulmonary valve regurgitation because of its rarity.