Bone scintigraphy is not performed routinely in the diagnostic work-up of children with leukemia; however, the initial diagnosis of childhood leukemia is often difficult to make and may be delayed. Patients may present with fever and skeletal symptoms and, in such cases, bone scintigraphy may be requested in the early search for a diagnosis. Recognition of the potential scintigraphic abnormalities that result from leukemic infiltration of bone and bone marrow will often facilitate an early diagnosis of leukemia. Bone scans also play a role in detecting osteomyelitis in the immunosuppressed leukemic child with fever and bone pain. This article presents four patients illustrating the salient features of bone scintigraphy in these clinical settings.