Thirty one (78%) of 40 consecutive patients (aged 13-79, mean 44 years) with infective endocarditis had congestive heart failure at presentation. Twenty six (65%) had had rheumatic heart disease and 17 (43%) patients had prosthetic valves. Eight (20%) patients had undergone dental procedures within three months of presentation. Blood cultures were positive in only 22 (55%) of the patients. In nine (41%) of them streptococci of the viridans group were isolated and in seven (32%) patients endocarditis was due to Staphylococcus aureus. Eight patients had Q fever endocarditis. Sixteen patients required operation because of haemodynamic deterioration while they were in hospital; 11 patients had native valves and five had prosthetic valves. Seven had emergency operations and were pyrexial at that time. Four of the seven died in hospital. Of the 12 who were alive and well after surgery only two required further surgery two and three years after the initial operation. Twelve (30%) of the 40 patients died in hospital; in 10 death was mainly due to left ventricular failure or congestive heart failure. All patients died who had renal failure (four cases), myocardial infarction (two cases), complete heart block (one case), or ventricular fibrillation (two cases) before operation. Six (33%) of the 18 patients with culture negative endocarditis died. Two of the four patients seen and treated more than 12 weeks after the onset of symptoms died, as did three of the five patients with prosthetic valves who required surgery while in hospital. Three patients with neurological complications survived and only two (29%) of the seven patients with blood cultures that were positive for Staphylococcus aureus died. Of these 40 high risk patients optimal antibiotic treatment and early surgery for haemodynamic difficulty ensured that 28 (70%) were discharged from hospital alive and well.