A 30-year-old man with a fever, cough, and dyspnea, was admitted to our hospital. A ruptured aneurysm of the Valsalva sinus (Konno classification, type I) was diagnosed associated with infective endocarditis of the aortic valve accompanied by aortic regurgitation (AR, grade II), and a ventricular septal defect (VSD, subarterial type). The operation was performed as follows: the removal of the aortic and pulmonary valves involved with endocarditis, the resection of the right aneurysm of the Valsalva sinus, and the myectomy of the fragile tissue of the right ventricle around the VSD. As a result, the large deficit region with the VSD and the resected right Valsalva sinus was patched with double sheets of equine pericardium. Aortic valve replacement (a prosthetic valve, ATS 18 AP) was anastomozed to the closed patch with the aid of the sheet as a part of the aortic valvular ring, and pulmonary valve replacement (a prosthetic valve, ATS 23 A) was done to the native pulmonary valvular site. During the 13 months after the surgery, under strict control of warfarin administration, the patient's clinical outcome has been favorable without infection and congestive heart failure. This case had AR accompanied with the subarterial type VSD, and aneurysmal formation of the Valsalva sinus and its rupture, and also revealed progressive infective endocarditis of the aortic and pulmonary valves, which resulted in severe cardiac failure. Early and appropriate surgical treatment for the ruptured aneurysm of the Valsalva sinus is required for a better prognosis prior to prevent exacerbation leading to infective endocarditis and critical heart failure.