Infective Endocarditis is caused by bacteria or fungi involving the heart or the great vessels (Endarteritis). It is a rare and potentially ominous disease, with increasing incidence. Despite technological advances it remains difficult to diagnose and treat, particularly in children below two years. Congenital heart disease is the main risk factor for Infective Endocarditis in children. A patent ductus arteriosus clinically silent is infrequently implied. Over two-month-old Streptococci spp and Staphylococcus aureus are the main agents, responsible for 62-77% of cases. Gram negative rods count for 4-6%, being Klebsiella pneumoniae a rare pathogen. The authors report a case of a previously healthy four-months-old infant, admitted for bronchiolitis. He developed a Klebsiella pneumoniae persistent bacteremia related to Endarteritis of a silent patent ductus arteriosus. After prolonged and successful antibiotic therapy, the ductus arteriosus was surgically closed. He suffered no complication during the disease process and recovered uneventfully
