The authors have studied the short and long term results of surgical treatment of acute phase of infectious endocarditis in a group of 33 high risk patients with valvular heart disease. The age varied from 2 to 68 years; 18 patients were male and 22 were of the white race. The aortic valve was most frequently involved (18/54.5%), followed by the mitral valve (13/39.3%) and tricuspid valve (2/6.0%). Twenty four patients (72.7%) were in functional class III and seven (21%) in functional class IV. The noninvasive studies in those patients revealed 13 cases (39.4%) with normal cardiac size. The ECG was abnormal in 27 cases (81.8%) mostly with left atrial and ventricular hypertrophy. The echocardiogram revealed the presence of vegetations in 27 patients (81.8%) and blood cultures were positive in 22 cases (66.6%). All patients were treated with antibiotics. The pathologic analysis revealed the presence of vegetations in 94% and structural alterations in 16.5%. Twenty-one patients had heart valve replacement with mechanical prosthesis (63.6%), 11(33.3%) had bioprosthesis and one had tricuspid excision without replacement (3.0%). The hospital mortality was 12% and the late mortality 3%. Three deaths occurred in patients who had prolonged clinical treatment (more than 65 days) and one patient died of severe fungal endocarditis. The follow-up of the remaining 26 patients varied from 01 to 448 weeks (mean 183) demonstrating important clinical improvement and a normally functioning valve prostheses. All patients are in functional class I and II. The analysis of our data indicates that surgical treatments is the best option for high risk endocarditis and should be undertaken earlier in all patients in this risk group.