BACKGROUND: Pneumonia ranks as a leading contributor to hospital admissions and mortality among children worldwide. This study aimed to investigate the association between aerosol components of air pollution and pediatric pneumonia hospitalization. METHODS: Employing an observational study design, data from hospitalized children under 15 years diagnosed with pneumonia in Thailand from 2015 to 2019 were analyzed to ascertain the relationship between air pollution and health outcomes. Utilizing the Modern-Era Retrospective analysis for Research and Application version 2 (MERRA-2) data for aerosol components, and adjusting for demographic and geographical factors, using Poisson regression models. RESULTS: A total of 732,700 children were hospitalized with pneumonia, with children under the age of five accounting for the majority of admissions (637,313 cases, 86.9%). Dust had the strongest association with the incidence rate ratio of hospitalization in children with pneumonia across all age groups. The incidence rate ratio was 1.288 (95% CI: 1.271-1.304, p <
0.001), 1.392 (95%CI: 1.344-1.442, p <
0.001), and 1.349 (95%CI: 1.265-1.439, p <
0.001) for children under the age of 5, 5 to under 10, and 10 to under 15, respectively. The association of hospitalization among children with pneumonia increased by 21.0% and 13.8% for each 1 μg/m3 increase in black carbon and dust levels, respectively. CONCLUSION: The findings reveal a compelling link between certain air pollutants and pediatric pneumonia hospitalization, highlighting the urgent need for targeted interventions to mitigate air pollution's adverse effects.