In the past 16 years, 2004 children with acute lymphoblastic leukemia (ALL) have been treated in the Polish Pediatric Group centers. Eight hundred and eighty-seven (44.3%) of these patients discontinued treatment after the first remission. Acute lymphoblastic leukemia relapse occurred in 180 patients (20.3%). This group was analyzed for the method of treatment and its influence on long-term survival, the time between cessation of treatment and relapse, the character and localization of relapse and later follow-up. It was shown that the patients with the best chance of a second remission are those with late testicular relapse. The most frequent and prognostically poor are bone marrow (BM) relapses which warrant intensive chemotherapy with BM transplantation. Patients with ALL relapse still have the possibility of a second remission and long-term survival.