Abstract Background: Community-acquired pneumonia is the most severe form of acute respiratory infections. Aim of Study: This study aimed to assess the role of copeptin as an early predictor of severity of community-acquired pneumonia in children. Patients and Methods: A case-control study was conducted on 53 children with community acquired pneumonia and another 40 children as controls with their gestational age, sex and weight matched, admitted to pediatric clinics from January 2021 to the end of December 2021. Blood samples for copeptin and procalcitonin were drawn and sent for analysis. Imaging techniques as X-ray, computed topography and ultrasound were used to assess the diagnosis of pneumonia. Results: Blood levels of copeptin in children with pneu-monia with a median of 65pmol/L were much higher than copeptin levels in controls with a median of 0.65pmol/L (P-value <0.001). Pneumonia complications were reported in 27 (50.9%) children. Higher severity scores as PRESS score, repertory illness score, bacterial pneumonia score, and PIRO score were reported in children with complicated pneumonia. Serum higher levels of copeptin and procalcitonin were reported in children with pneumonia compared to the control groups (p-value <0.001). Conclusion: Serum blood levels of copeptin might be used as a diagnostic and prognostic biomarker for community-acquired pneumonia.