Background Nosocomial infections remains a leading cause of morbidity and mortality in Neonatal Intensive Care Unit(NICU).

Aim To assess incidence, etiology and outcome of culture-proven nosocomial sepsis in low birth weight(LBW) infants.

Methods Retrospective study of preterm infants with birth weight < 1500g and proven nosocomial sepsis admitted in NICU of Hospital Carlos Haya during 2011.

Results Sixty neonates experienced at least one or more episode of nosocomial sepsis out 160 LBW infants meaning an incidence of 37.5%. 61% positive blood culture. Table one. Mortality was 6.6% of all patient with proven sepsis and 4% of all positive blood culture. In our series fungal sepsis were the most aggressive being responsible of the 50% of deaths.

Conclusions Overall infections rate is similar to the current reports for level 3 hospitals. Gram positives organisms were common being S. epidermidis the most frequent. Related to gram negative K. pneumoniae, S. marcensces and Enterobacter were the most frequently isolateded. No cases of expanded spectrum of betalactamases bacterial. Mortality is less than previously reported.