Despite recent advances in antimicrobial therapy infective endocarditis (IE) still remains a major surgical problem. All patients undergoing surgical treatment for IE at our Institution since 1970 were reviewed; among these in 40 IE was considered to be active at time of operation. Thirty patients were males and 10 females, ranging in age from 11 to 66 years (average 41); indications for operation were heart failure in 31, mycotic emboli in 5, and sepsis in 4. Nine were in NYHA functional class 11, 18 in NYHA class III, and 13 in class IV. Aortic valve replacement (AVR) was performed in 24 cases, mitral valve replacement (MVR) in 5 and multiple valve replacement (PVR) in 11. Overall hospital mortality was 15% (4.2% in the AVR group, 40% in the MVR group, and 27% in the PVR group). Postoperative follow-up was available in all survivors. Four patients died in the late postoperative period for not infective causes. Almost long-term survivors show, from 7 months to 10 years (average 58 months) postoperatively, a significant improvement. No complications related to the initial infective process were recorded. According to the results of the present study the following conclusions can be drawn: 1) active IE does not represent a contraindication to open heart surgery and prosthetic valve replacement; 2) the surgical results depend not only on the degree of cardiac failure, but mainly on its duration; 3) early surgical intervention affects favourably the prognosis, especially in cases of isolated aortic valve involvement; 4) the surgical management of IE removes the focus of infection.