Acute respiratory infections (ARI) are the leading cause of pediatric morbidity and mortality worldwide. Information on etiological agents of ARI in developing countries is still limited. This study conducted in Alexandria, Egypt, was designed to determine the prevalence of several microorganisms in 113 children hospitalized with ARI. Overall, 65 agents were identified; 58 (51.3%) individuals were found to be positive for at least one pathogen, and seven of them were also positive for two agents. Chlamydophila pneumoniae was the most commonly detected agent (n=32; 28.3%), followed by Mycoplasma pneumoniae, respiratory syncytial and influenza. Positivity for C. pneumoniae, which was the most commonly detected agent, was associated with male sex and with mild disease of the upper respiratory tract.