To determine the etiological profiles of lower respiratory tract infection (LRI) in neonates during respiratory syncytial virus(RSV) season, and to define the clinical features of RSV-related infection and others.The retrospective study included newborn infants who were hospitalized for LRI during the two consecutive RSV seasons, and then tested for possible etiological agent by multiplex real-time polymerase chain reaction. All relevant data were reviewed, and the clinical characteristics of RSV-related infection were compared to those of others.Of 224 patients, 160 (71 %) were positive for at least one potentially causative agent. Of them, 65 % had RSV, and 15 % had more than on ecausative agent (co-infection). The RSV group had more the findings of respiratory distress (p< 0.01), abnormal chest radiography (p< 0.01), need for intensive care (p< 0.01), and duration of oxygen requirement (p< 0.01) but less fever on admission and duration of antibiotic use (for both, p< 0.01), and no longer hospital stay. Need of intensive care nursery was more common in patients with co-infection than others (25 % vs. 6.5 %, p< 0.01).This study highlighted that RSV was the most frequent agent in neonates hospitalized for LRI during the season, with a more severe clinical course than other detected pathogens. The disease severity of RSV infection may have seemed to be increased by the presence of coinfection and abnormal chest radiography.