Double-chambered right ventricle is a rare heart defect causing right ventricular outflow tract (RVOT) obstruction. In this malformation, the right ventricle is divided into two chambers by a fibromuscular band. A 12-year old female patient who had undergone repair of a ventricular septal defect at 5 months old was admitted to our hospital with complaints of dyspnea and fatigue. The patient was diagnosed with an isolated double-chambered right ventricle and surgical correction was successfully performed. Postoperative transesophageal echocardiography showed no residual gradients across the RVOT. Following an uneventful recovery, the patient was discharged five days after surgery.