Background: Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in children worldwide, particularly in low- and middle-income countries. Clinical signs and radiological findings alone may be insufficient to predict disease severity. In this context, biomarkers such as procalcitonin (PCT), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) have been studied as potential predictors of severe pneumonia. Objective: To evaluate the role of serum procalcitonin in predicting the severity of community-acquired pneumonia in children and to compare its performance with serum CRP and ESR. Materials and Methods: This cross-sectional analytical study was conducted in the Department of Pediatrics, Bangladesh Medical University, Dhaka. A total of 60 children aged 2 months to 5 years who fulfilled the WHO criteria for CAP were enrolled. Children were categorized into pneumonia, severe pneumonia, and very severe pneumonia groups based on WHO guidelines. Clinical examination and demographic data were recorded. Serum PCT was measured using the Atellica IM BRAHMS PCT assay, CRP by latex agglutination, and ESR by standard methods. Statistical analysis was performed using SPSS version 25. Receiver-operating characteristic (ROC) curves were generated to determine sensitivity, specificity, and cutoff values of biomarkers in predicting severe CAP. A p value <0.05 was considered significant. Results: The mean serum PCT level was significantly higher in children with severe/very severe pneumonia (12.93 ± 10.12 ng/ml) compared to those with pneumonia (1.53 ± 0.81 ng/ml) (p<0.001). Similarly, CRP (70.75 ± 37.10 mg/dl vs. 16.12 ± 14.79 mg/dl, p<0.001) and ESR (36.87 ± 13.98 mm/hr vs. 26.0 ± 8.15 mm/hr, p<0.001) were elevated in severe cases. ROC curve analysis demonstrated the highest diagnostic accuracy for serum PCT (AUC = 0.942, sensitivity 94.9%, specificity 70.0%) compared to CRP (AUC = 0.912) and ESR (AUC = 0.738). Conclusion: Serum procalcitonin is a highly sensitive and specific biomarker for predicting the severity of community-acquired pneumonia in children, outperforming CRP and ESR. Incorporation of PCT measurement in routine clinical practice may aid in early identification of severe cases and guide timely management.