Pneumonia is an acute inflammatory disease that we find mostly in the pediatric population; it consists of inflammation of the lung parenchyma, occupying the air space with the involvement of the interstitial space depending on the atomic area that is involved (alveolar, interstitial or bronchial). According to (WHO) and (UNICEF) in 2015 established that 920,136 children under five years of age died from this pathology, 2,500 children per day; which is equivalent to 100 per hour. It is a non-experimental research, with analysis of descriptive correlational character and with quali-quantitative approach, for which was used as a source of information a Database of patients made under the diagnosis code CIE-10 J18, corresponding to Pneumonia, Unspecified Organism, provided by the Statistics Department of the Hospital del Norte de Guayaquil IESS Ceibos. An analysis focused on the etiology of the pediatric patients from 3 to 5 years of age was carried out, where the predominant bacterial pneumonia was S. Pneumoniae with (36.22%) of the cases, which corresponds to 46 of 127 cases that were part of the study.