The dramatic success of the therapy of acute lymphoblastic leukemia (ALL) over the past 60 years has led to significantly improved survival of pediatric patients and, to a lesser extent, adult patients with ALL. With this success has come the recognition of late sequelae of chemotherapy and radiation treatment of long-term survivors of ALL therapy. These late consequences encompass complications of nearly every organ system, but dominantly affect neurocognitive, endocrine, and cardiac systems. The endocrine effects are the most pleomorphic and impact growth, body weight, fertility, thyroid function, and bone metabolism. Second malignancies are also a serious complication of therapy. Patients who undergo blood or marrow transplantation as part of the therapy for ALL are at risk for similar complications. Increasing recognition and study of these complications has led to the development of monitoring schedules and the development of guidelines for managing patients who are long-term survivors. [ABSTRACT FROM AUTHOR]