This study has been carried out with the aim of assessing the incidence and other features of Infective Endocarditis in the region Veneto (Italy) in the years 1975-84, with particular regard to the patients admitted to the hospitals in Verona. Of the 692 patients admitted in hospitals of Veneto, 629 were resident in the region (an incidence equal to 1.6/100,000 inhabitants per year). The age range was from 8 to 72 (55 +/- 9). All social classes were affected, although retired, disabled and unemployed subjects were in the majority. The average stay in hospitals was 27.6 days. In 7.6% of the cases surgical therapy was required; the over-all mortality rate was 10%. Of the 80 patients admitted to the hospitals in Verona, 79% were suffering from pre-existing cardiopathy (40% rheumatic heart disease, 25% valvular prosthesis, 7.5% congenital heart disease, 5% prolapsing mitral valve, 1.2% obstructive hypertrophic cardiomyopathy); 54% of the cases had been exposed to bacteriological infections in the preceding months: bronchopulmonary, oropharyngeal, genitourinary or gall bladder infections processes or oral surgery or heart surgery or drug addiction. Only in 19% of these cases a correct antibiotic prophylaxis had been carried out. The responsible germ was identified in 50 patients (67% of the cases in which blood cultures had been performed): Streptococcus in 22%, Staphylococcus in 20%, Gram-negative in 12%, Corynebacterium in 4%, polymicrobial associations in 9% of the cases. These data stress the need for an improvement in antibiotic drug regimen (both in prophylaxis and treatment) and the diffusion of norms of hygiene aimed to the reduction of skin and mucous sources of bacteremia and interpersonal transmission of infections disease.