Objectives: To demonstrate the value of FDG PET/CT in evaluation of childhood patient with osseous Langerhans cell histiocytosis (LCH). Patients and Methods: A prospective analysis of 24 pediatric patients with histopathologically proven LCH September 2016 till November 2018. All patients received specific therapy for LCH in the form of chemotherapy &/or surgical resection. Analysis criteria included the following: any focal FDG uptake was considered abnormal when it was greater than that of hepatic uptake or in presence of abnormal changes on CT with any degree of FDG uptake. Results: 17 patients (70.8%) presented with multi-system disease (bone as well as LNs &/or liver, lungs, soft tissueand skin), 5 patients (20.8%) had uni-focal osseous lesions and 2 patients (8.3%) presented by multi-focal bone lesions. FDG PET/CT revealed metabolic changes in osseous lesions detected by anatomical radiographic scan and revealed multiple other lesions as well. No statistically significant association could be detected between neither disease recurrence nor risk of mortality at diagnosis with age, sex, presenting organ, disease extent, risk of mortality, SUV max of leading lesion. Conclusion: PET/CT may be useful as additional imaging to assess known LCH lesions and rule out the presence of other organ infiltration and to provide a reference basis of staging, treatment plan.FDG PET/CT provides the characteristics of lesions in CT scan, but also the lesions activity by FDG uptake. 18F-FDG PET/CT may be incorporated in patientmanagement to facilitate disease stratification and avoid un-necessary interventions.