Twenty-six of 163 patients with infective endocarditis treated between 1969 and 1979 required operation. The consequences of infection in these 26 patients included leaflet destruction, annular "ring" abscess, fistula formation with ventricular and atrial septal perforation, and myocardial abscess with heart block. Surgical principles used to repair these abnormalities successfully were excision of necrotic tissue, valve replacement, repair of annular defects, and closure of perforations. Temporary and permanent cardiac pacing were used also. The operative mortality was 13%.