The use of central venous lines in neonatal intensive care is widespread. We report a series of 11 infants in whom extravasation of fluid developed presumably as a result of the central line. There were six cases of pericardial effusion with a 67% mortality rate and five cases of pleural effusion with no mortality, for a total extravasation incidence of 1.1% for central lines placed during a 5-year period. The highest incidence of effusion occurred with polyethylene catheters, but all types of catheters resulted in effusion. This report emphasizes the serious morbidity and mortality of these complications of central venous lines.