We conducted a retrospective evaluation to determine the clinical and microbiological characteristics of 61 episodes of infective endocarditis (IE) in intravenous drug abusers (IDA), HIV seropositive patients. Forty-nine males and 6 females between 15 and 42 years of age were included in the study. All the included patients presented 61 episodes of IE. Fever and cardiac murmur were present in all episodes; 43 (70.4%) had hepatomegaly; 29 (47.5%) had splenomegaly. Thirty-eight (62.3%) presented cough (9 with hemoptysis); 25 (41%) had dyspnea, and 5 (8.2%) had jugular ingurgitation. Fundoscopy showed alterations in 3 patients (4.9%). Bacteriological confirmation was obtained in 41 episodes (67.2%); blood cultures revealed Staphylococcus aureus in 30 cases (73.1%), Streptococcus viridans in 8 (19.5%) patients, Staphylococcus epidermidis in 1 (2.4%), Staphylococcus hominis in 1 (2.4%) and Streptococcus pneumoniae in one case (2.4%). The tricuspid valve was involved in 51 episodes (83.6%), the aorta in 6 (9.8%), the mitral valve in 3 (4.9%) and the pulmonary valve in one (1.6%). There was evidence of right bivalvular involvement in 2 patients (3.2%) and tricuspid and mitral involvement in another (1.6%). Pericardial effusion was detected in 19 episodes (31.1%). Six patients (10.9%) died during the acute episode of IE.