Hospital records of forty-nine patients with a diagnosis of bacterial endocarditis at the University of Kentucky Medical Center Hospital from 1963 to 1975 were reviewed. Data collected and statistically analyzed resulted in the following conclusions: 1. Bacterial endocarditis affected males three to four times as often as females. 2. Morbidity was significant, with an average hospital stay of 4 weeks. 3. The mortality rate among the entire group of patients was 42.8 per cent. A significantly higher rate of 66.7 per cent was noted in patients with prosthetic heart valves. 4. The most prevalent predisposing factor was rheumatic heart disease. 5. There were five cases (10.2 per cent) in which dental procedures were the probable precipitating cause, once again pointing out the importance of detecting susceptible patients and proceeding with dental therapy only after adequate prophylactic measures. 6. The most frequently isolated microorganism was Staphylococcus aureus. 7. Chloramphenicol was the most effective in vitro antiboitic tested, with erythromycin a close second. Although it might appear that penicillin was not as effective, the concentration in actual usage may differ significantly from that in the tested discs. Penicillin, therefore, still remains the foundation for treatment in susceptible cases.