Background: Adenovirus (ADV) is an important agent in acute respiratory tract infections that may produce high morbimortality. Objective: Describe epidemiological and clinical characteristics of ADV respiratory infections and identify possible associated factors for severity, mortality and broncho-pulmonary consequences. Method: Review of clinical files of patients with diagnosis of ADV respiratory infection during 2004 by inmunofluorescence assay. Clinical and epidemiological data were registered. Risk factors and rate of attack were calculated. Results: 57 patients, 68,4% males with medium age 10 months-old (67% less than 1 year-old) were included. 89,5% were hospitalized; 26,3% presented severe outcome, 8,8% died and 47,3% presented bronchopulmonary sequelaes. During this period, 2 intrahospitalary infection outbreaks were observed, with a rate of attack of 16,5%. Risk factors for severe illness were identified: age between 4 and 10 months-old and ADV acquired during an intrahospitalary outbreak infection. For mortality, the history of underlying illness and, for bronchopulmonary consequences, age between 4 and 10 months-old. Conclusions: Risk factors identified should notice our attention in children hospitalized with diagnosis of Adenovirus, since they can predict an unfavorable outcome