An 18-day-old baby was admitted to our hospital with irritability and preauricular swelling. He was born at term, as one of twins, and weighed 2540 grams. Physical examination revealed that his weight and head circumference were normal for his age. His vital signs were as follows: body temperature 37.4ºC; heart rate 130/minute; respiratory rate 50/minute; and blood pressure 80/50 mmHg. He had a mass at the right preauricular area, septic arthritis of the right wrist and left knee, a generalised macular rash, and pretibial edema on physical examination. Leucocytosis, thrombocytopenia, and high acute phase reactants were detected on the laboratory studies. Blood biochemistry was normal except for low total protein and albumin levels. Echocardiography revealed a large vegetation on the tricuspid valve, but it did not cause any hemodynamic disturbance. Cardiac chambers and systolic functions were normal. These clinical and echocardiographic findings were suggestive of infective endocarditis and wide-spectrum antibiotics (vancomycin, ceftazidime, amikacin) were started. Blood and abscess cultures were positive for S. aureus. The abscess in the knee was drained surgically while the abscess on the neck drained spontaneously. Cardiac surgery was not performed for this patient as there was no clinical hemodynamic disturbance or peripheric embolization. Complete recovery was obtained after using intravenous antibiotics for 6 weeks. S. aureus bacteremia in neonates can lead to the deep tissue infections and infective endocarditis, and routine echocardiographic screening should be performed in these neonates even if there are no clinical findings

Keywords: Bacteremia, Infective endocarditis, Staphylococus aeurus, Newborn