INTRODUCTION: Viral respiratory infections cause major morbidity and mortality in preterm infants. We have performed a prospective study in our neonatal intensive care unit (NICU) to determine the incidence of respiratory infections, their impact and the epidemiology and outcome in high risk neonates. PATIENTS AND METHODS: From September 2011 to May 2013 a prospective study was conducted in all preterm infants < 32 weeks gestational age and in all term newborns admitted to NICU for any pathology that are anticipated to have an income exceeding two weeks. A nasopharyngeal aspirate (NPA) was collected the first day of life and weekly until discharge for virologic study with polymerase chain reaction. When these babies presented respiratory symptoms a new NPA was collected in this moment. A clinical form was filled by the physician. RESULTS: A total of 60 infants were analyzed: 30 (50%) had a gestational age < 32 weeks and 36 (60%) weighing less than 1500 grams. We collected a total of 256 nasopharyngeal aspirate samples, 24 of them being positive (9.3%). These 24 positive samples corresponded to 13 infants in our cohort (21.6% of the patients). Of them, 9 were symptomatic and had 11 episodes of infection (2 patients had two different episodes with negative control between them). The most frequently identified virus was rhinovirus in (19) 79% of cases. The most frequent clinical data was the presence or increased of apneas (75%) and the needed of oxygenotherapy. CONCLUSIONS: HRV infections are prevalent in the NICU, and preterm infants have a high risk of infections with clinical relevance.