We studied five patients with acquired ventricular septal defect during the course of an infective endocarditis. All patients were male and had a previous aortic valve disease associated with an aortic ring abscess. Clinical examination was useful for the diagnosis of 4 cases, emphasizing the following findings: systolic murmur and/or left paraesternal thrill and right-heart failure. Incidence of congestive heart failure was 60//, while 40//of all patients died during the in-hospital course. No specific etiologic agent was detected. Therefore, acquired ventricular septal defect should be suspected in patients with infective endocarditis of the aortic valve that evolve with a systolic murmur and/or paraesternal thrill and right-heart failure. Immediate surgical treatment is mandatory in these cases