Leukemia is a curable disease with unknown etiologyin the pediatric age group. Cure rates approaching 75% can be achieved with combination chemotherapy but this percentage disguises success rates that vary from 10% to 90% with the different biological and clinical subtypes of the disease. Studies pointing to environmental factors such as infections and chemical exposures indicate possible risk factors in childhood leukemia. Primary prevention should remain an ultimate goal, along with further advancements in therapeutic and control of infection. In this review current data for the etiology, diagnostic and therapy modialities are discussed.