Double-chambered right ventricle [DCRV] as a clinical and anatomic entity was separated from other forms of right ventricle obstruction, and frequently associated with VSD. We experienced surgical treatment of 6 cases of DCRV with VSD. Among them, PDA in a case, PFO in two cases and one case of mild infundibular PS were associated. Preoperative cardiac catheterizations and RV cineangiograms showed about 69 mmHg. of pressure gradient in average between RV inflow and outflow portion, and filling defect by anomalous muscle bundles in the sinus portion of RV. On operation, VSD and other associated anomaly were corrected after resection of anomalous muscle bundle for relief of the obstruction through the vertical RV-tomy site. Postoperative EKG showed complete RBBB, but hemodynamic problems were not developed. Postoperative cardiac catheterizations showed markedly decreased pressure gradient between two chambers, that was about 15 mmHg. in average. Postoperative course was smooth and discharged without any problems.