Bacterial endocarditis was the cause of heart valve destruction in 23 patients. Additional 5 patients were reoperated because of an infected valve prothesis. 13 were operated upon during the inactive stage. Nevertheless infection recurred after operation at least in one patient. 10 patients underwent operation during the active stage, 6 of these with stable cardiac function, 4 in cardiogenic shock. Hospital mortality was 2/6 and 1/4 respectively. One patient died after three months of persisting infection. Three of five patients with infected valve prosthesis survived reoperation. An attempt is made to define the indication for valve surgery in bacterial endocarditis.