The authors reported on a 11 day-old child, admitted in Neonatal Intensive Care Unit for multiple congenital malformations, who had sepsis and bacterial endocarditis. Among the risk factors for endocarditis were outstanding: the central venous catheterism, hemoculture with growth of Staphylococcus aureus and mechanical ventilation. The diagnosis was made in the 61st day after admission owing to the presence of persistent fever and appearance of systolic murmur. The echocardiogram revealed a thrombus in the right atrium measuring 1.9 x 0.7 mm. Antibiotic therapy and surgical resection being performed, with clinical improvement. On the 125st day after admission the patient died owing sepsis and cerebral abscess. At necropsy, heart malformations were not observed. The authors concluded to be very important the knowledge of the potential risks of invasive procedures currently used to care for critically ill newborns. The clinical suspicion of endocarditis should be considered in all neonates with sepsis and receiving intensive care for long time.