Background: The aim of this study was to investigate the role of Neopterin in evaluation of severity and outcome of pneumonia in pediatric Department of Zagazig University Hospitals. Methods: A prospective case control study was carried out at the pediatric Department of Zagazig University Children Hospitals during the period from November 2017 to December 2018 .sixty infants and children patients participated in the study 40 were diagnosed as pneumonia admitted to Pediatric Department of Zagazig University as case group And twinty infants and children of control. Serum level of Neopterin was measured for all patients recruited in this study, by a commercial ELISA assay. Results: In our study there was statistically significant difference between case and control groups in Neopterin level, there is statistically significant difference in Neopterin level between cases that need ICU admission and M.V. and cases treated in ward only without need , there was statistically significant difference in Neopterin level between survivors and non-survivors. In this study, there was statistically significant difference in Neopterin level with disease severity.in which Neopterin is higher in severe than moderate and mild cases. Our study shows that there was statistically significant positive correlation between Neopterin level and total PRESS score, granulocytes and CRP. In our study we tried to detect the cutoff point of Neopterin to detect severe pneumonia calculated from ROC curves it was > 13.93 (nmol/L), and the area under the curve of Neopterin was0.866 with sensitivity 92.3% and specificity 77.8%. Conclusion: Neopterin is a useful prognostic and diagnostic marker for pneumonia in Pediatrics. The present study suggests that Neopterin is a promising biomarker for reflecting the severity of Pneumonia.