To better understand the microbiology, anatomy, and demography of infectious endocarditis, we devised a prospective statewide reporting system to study these infections. Because our study design required accurate diagnosis, reliable case reporting, and a high probability of physician-to-case exposure, we enlisted the help of cardiologists, cardiovascular surgeons, and infectious disease specialists throughout Louisiana. All Louisiana members of the American College of Cardiology and the Infectious Diseases Society of America were invited to participate. Participants were supplied with a brief endocarditis report form and asked to complete the form as they saw patients with infective endocarditis. Seventy-five patients with infective endocarditis were reported for a case rate of 1.7 per 100,000 persons per year. This report analyzes the results from this one-year study.