Objective. To describe the demographic characteristics, etiologic agents, some associated factors and, the resistance pattern of the microorganisms in neonates identified with nosocomial infections at the Neonatal Intensive Care Unit of Fundación Cardioinfantil in Bogotá. Study design. This retrospective study was developed from 20 04 to the first trimester of 2006. Nosocomial infection was defined as the infection diagnosed after 72 hours of hospital admission in a neonate who received antimicrobial therapy during more than three days. Results. Sixty clinical medical charts were reviewed. Gram-negative organisms were the most frequent agents (71.2%) causing nosocomial infections acquired within or outside of the institution. Klebsiella pneumoniae was the agent most frequently identified with 65% of resistance to third generation cephalosporin. Conclusion. Gram-negative are the predominant etiologic agents responsible of nosocomial infections in neonates admitted to the Fundación Cardioinfantil.