ObjectiveTo determine the clinical and demographic characteristics of pneumonia with influenza virus AH1N1/2009 pandemic at the National Institute of Child. Methods. Retrospective case series in children hospitalized for influenza pneumonia pandemic AH1N1/2009 in a pediatric hospital. Reviewed the medical records between the months of June to September 2009. All cases had virological confirmation, we describe the clinical characteristics and conditions of severity. Results. A total of 74 children of pneumonia with influenza virus AH1N1/2009 pandemic (NVIp), of those 50 were community acquire pneumonia viral (NACv) and 24 pneumonia nosocomial viral (NNv), 16 required mechanical ventilation. 12 died, all had preexisting factors. NN cases showed statistical association with mortality. The most frequent factors were malnutrition, respiratory infections, congenital heart disease and neurological deficits In NACv cases the children under 6 years accounted for 72% (36/50). The median disease duration was 5 days. The most frequent symptoms were fever, cough, runny nose. Received oseltamivir 82%. The chest radiograph 48% of cases showed patchy infltrates and 44% interstitial infiltrate on chest radiograph. Protein c reactive (CRP) more than 10mg/L was significantly associated with respiratory failure (p <0.05). Conclusions. Cases of NN found who had more mortality, even those who had the highest PCR and those with preexisting condition.