Our objective was to evaluate the value of (18)F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) versus diagnostic contrast CT in the initial staging of pediatric Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL). Thirty patients with HD and 21 patients with NHL were included in this retrospective study. On nodal lesion analysis, PET/CT detected 94.8% (HD) and 88.3% (NHL) of total lesions, respectively, in contrast to 82.6% (HD) and 69.1% (NHL), respectively, for diagnostic contrast CT. PET/CT also detected more extranodal lesions. On the patient level, PET/CT detected additional lesions in 50% of patients with HD and in 42.9% of patients with NHL. In contrast, diagnostic contrast CT detected additional lesions in 16.7% (HD) and 23.8% (NHL) of total cases. FDG PET/CT led to upstaging in seven cases of HD and seven cases of NHL, while diagnostic contrast CT upstaged two cases of NHL. We conclude that FDG PET/CT outperforms diagnostic contrast CT in the initial staging of pediatric patients with lymphoma.