This retrospective study describes 100 cases of infective endocarditis (IE), collected between 1980 and 2004. Patients were subdivided into 2 groups, according to the use of trans-esophageal echocardiography (TOE) in the institution where the study was performed: group A (GA=55 patients, between 1980 and 1991) and group B (GB=45 patients, between 1992 and 2004). The IE cases of 59 men and 41 women were analyzed. Patients had a mean age of 33 years (range 15-75 years). An underlying heart disease was involved in all cases, mainly rheumatic heart disease (93% of cases). Native valve endocarditis (NVE) was seen in a majority of cases (93%), and the localization of IE was aortic in 36 cases, mitral in 36 cases, mitro-aortic in 26 cases and mitro-aortic-tricuspid in 2 cases. Prosthetic valve endocarditis (PVE) occurred in 12 cases. Blood cultures were positive in 31 cases, with 14 staphylococcal infections (3 in GA and 11 in GB) (p < 0.05), of which 6 were coagulase-negative; 13 were streptococci and 4 were Gram negative bacilli. All patients had a transthoracic echocardiography (TTE), and patients in group B also had a TOE. Seventeen patients had a favorable outcome without need of a surgical intervention. Early surgery was necessary in 71 cases (85.5%), and elective surgery in 12 cases (14.5%). Mortality while awaiting surgery was 27%, and has been decreasing for the past decade (41.8% in GA and 8.9% in GB) [p < 0.05]. Postoperative mortality after early surgery intervention was 13.6% (6 among 44 patients), and it was 8.3% (1 among 12 patients) after elective surgery intervention. Overall mortality was 34%: 27 deaths with NVE (30.7% [27/88]), and 7 deaths with PVE (58.3% [7/12]) [NS]. Predictors of mortality in this observational study were positive blood cultures involving staphylococci, the presence of valve mutilations, unstable prostheses, and heart failure.