The study was conducted at the Children’s Cancer Hospital in Cairo. A total of sixty two patients who performed one hundred and fifty five PET/CT studies (17 girls and 45 boys) with histologically proven malignant lymphoma (56 HD, 6 NHL) were included in this study. They were divided into four groups according to the indication of PET/CT study. Group I: 62 studies for initial staging. Group II: 35 studies for evaluating early treatment response after two to three cycles of chemotherapy. Group III: 27 studies for evaluating treatment response 4–8 weeks after the end of their treatment. Group IV: 30 studies evaluated for follow-up and detection of relapse. Results of PET/CT were compared with diagnostic CT.