Nosocomial sepsis is a serious problem for neonates who are admitted for intensive care. As it is associated with increases in mortality, morbidity, and prolonged length of hospital stay, both the human and fiscal costs of these infections are high. Although the rate of nosocomial sepsis increases with the degree of both prematurity and low birth weight, no specific lab test has been shown to be very useful in improving our ability to predict who has a "real" blood-stream infection and, therefore, who needs to be treated with a full course of antibiotics. As a result, antibiotic use is double the rate of "proven" sepsis and we are facilitating the growth of resistant organisms in the neonatal intensive care unit. The purpose of this article is to review the topic of nosocomial infections in neonates.