Childhood pneumonia represents an important pathology, a cause of morbidity and mortality worldwide. Our study aims to determine etiology of pneumonia in hospitalized children using several laboratory methods. We performed a prospective study that enrolled 560 children age 1 up to 18 years old all diagnosed with pneumonia by clinical and radiological features. We applied various laboratory methods (serologic, bacteriologic: bronchial aspirate, sputum, pleural effusion and blood culture) in order to identify a pathogen agent that caused pneumonia. Statistics used Statistical Package for Social Science. An etiology was established in 68.92% of all cases included in the study, as follows: in 33.93% viral etiology, in 25.13% we identified Streptococcus pneumoniae, in 20.2% Mycoplasma pneumoniae, Klebsiella pneumoniae in 8.29%, Staphylococcus aureus in 7.51%, Haemophilus influenzae in 4.92%. Mixed bacterial and viral infection was identified in 4.40% of all cases. A potential causative agent of childhood pneumonia was determined in most cases, S. pneumoniae being the main agent involved in community acquired childhood pneumonia in our country.