Osteonecrosis is recognized increasingly as a complication of the treatment of cancer in young people, especially those with acute lymphoblastic leukemia and non-Hodgkin lymphoma, reflecting a probable pathogenetic role of steroid therapy. Children ≥10 years of age and Whites are at particular risk, and genetic predispositions have been identified. The disorder affects weight-bearing joints predominantly. It is commonly bilateral and multi-articular. Treatment options include both surgical and non-surgical interventions. Pediatr Blood Cancer 2008;50:483–485. © 2007 Wiley-Liss, Inc.