Osteoporosis in children with leukemia can affect quality of life if it is not recognized in time. Only few reports have addressed this problem so far. Roentgenological alterations in the skeleton of children with acute lymphoblastic leukemia (ALL), compatible with loss of bone mass, can be found at diagnosis . Some children even have collapsed vertebrae before leukemia treatment has been started. At least two major components of ALL treatment can cause further loss of bone mass: corticosteroids  and methotrexate . The role of other chemotherapeutic agents is less clear. From 1987 we have estimated the presence of osteoporotic changes, studying bone mineral content in children with ALL.