A 610 g infant born after 27 weeks of gestation required central venous infusion therapy by a 23 gauge silastic catheter with its tip located in the superior vena cava. During adequate antibiotic therapy for sepsis the infant developed cardiac tamponade with circulatory failure. Therapeutic pericardiocentesis revealed pericarditis and not hydropericardium. Central venous infusion could be continued relapse-free without a change in catheter position. After bacteriologic identification of Staphylococcus epidermidis in blood culture and pericardial aspirate, the central venous line was removed and identified as the source of infection by identical bacterial growth from the catheter tip. While cardiac perforation has been recognized as a rare complication of central venous infusion even by very soft and thin silastic catheters, this is to our knowledge the first report on cardiac tamponade from bacterial pericarditis following catheter sepsis in a neonate.