The primary objective of this review was to update and discuss the current concepts andthe results of the treatment of acute lymphoblastic leukemia (ALL) in adolescents and young adults(AYA). After a brief consideration of the epidemiologic and clinicobiologic characteristics of ALLin the AYA population, the main retrospective comparative studies stating the superiority ofpediatric over adult-based protocols were reviewed. The most important prospective studies inyoung adults using pediatric inspired or pediatric unmodified protocols were also reviewedemphasizing their feasibility at least up to the age of 40 yr and their promising results, with eventfreesurvival rates of 60-65% or greater. Results of trials from pediatric groups have shown that theunfavourable prognosis of adolescents is no more adequate. The majority of the older adolescentswith ALL can be cured with risk-adjusted and minimal residual disease-guided intensivechemotherapy, without stem cell transplantation. However, some specific subgroups, which aremore frequent in adolescents than in children (e.g., early pre-T, iAMP21, and BCR-ABL-like),deserve particular attention. In summary, the advances in treatment of ALL in adolescents havebeen translated to young adults, and that explains the significant improvement in survival of thesepatients in recent years.