We report the imaging findings and natural history of avascular necrosis of bone (AVN) that developed following a chemotherapy regimen including high dose steroid treatment. All patients had acute lymphoblastic (ALL) or non-Hodgkin's lymphoma (NHL). Symptoms followed the high dose steroid therapy and 28 joints in eight patients were involved, (11 knees, seven hips, five shoulders and five ankles). Plain radiographs at presentation were normal in most joints, whilst bone scintigraphy and magnetic resonance imaging (MRI) were positive. We believe that the development of AVN in these patients is most likely due to the high dose dexamethasone therapy as in all eight cases symptoms followed this stage of the regimen. Patients experiencing bone or joint pains while receiving high dose steroids as part of a chemotherapy regimen could be investigated by bone scintigraphy but MRI is preferable as it is more sensitive and specific for AVN. In this series of patients multiple joints were involved and all the male patients proceeded rapidly from bone infarction to joint collapse. If the MRI appearances are typical, an early diagnosis of AVN can be made enabling therapeutic interventions to prevent joint collapse and its associated morbidity.