Introduction. The congenital heart disease (CHD) has become a major risk factor for infective endocarditis (IE) due to a large number of children with CHD that survive until adulthood. The incidence of IE in children with CHD is reported to be approximately 4.1 cases per 10000 persons/year, but in adults – 11 per 10000 patients/year with a marked variation between different types of CHD. The progress in diagnostic and surgical field, as well as the use of intracardiac devices and prosthetic materials increases the risk of associated infections and developing IE. As for causative pathogens, streptococci species predominates over the staphylococci species. Aim of the study. Evaluation of patients with infective endocarditis due to congenital heart disease. Materials and methods. The study included 262 patients with definite IE (mean age 51±7 years) that have been examined after clinical and paraclinical parameters. The patients with IE were divided into two groups: I – IE caused by CHD (17.2%), group II – IE due to acquired heart disease (AHD) in 82.8%. Results. The diagnosis of IE was established earlier in patients with CHD – up to 5 months, while in patients with AHD – up to 12 months. Hemocultures were positive in 44.4% vs 30.9%, streptococci predominating in group I (22.2%) and staphylococci in group II (15.6%). Clinically, the manifestations of the toxi-infectious syndrome (fever, chills, sweating, fatigue) prevailed in both groups – 93.3 % vs 91.7% and heart failure (dyspnoea, cough, palpitations) in 71.1% vs 89.4 %. Echocardiographic vegetations have been diagnosed in 77.8% vs 68.2%, followed by chordae breakages (26.7% vs 18%) and pericardial effusion (15.6% vs 19%). Registered complications – neurological – 15.6% vs 14.7%, renal – 15.6% vs 9.7%, while embolic episodes were reported less often – 13.3% vs. 17.5%. The overall outcome in patients with CHD is more favorable, with a 100% survival rate, compared to 93.5% in group II. Conclusions. IE in patients with CHD diagnosed earlier, has a more benign evolution. Streptococci were the causative agents in a greater percentage, such complications as toxic shock syndrome and heart failure prevailing. Echocardiographically vegetations, chordae breakage and pericardial effusion were detracted, while such complications like the neurological and renal, embolic episodes developed more rarely, with a better prognosis than in patients with AHD.