The Hungarian Pediatric Oncology Study Group treated 362 acute lymphoblastic leukemia patients between 1990 and 1995 using the the ALL-BFM 90 protocol. The modified protocol, ALL-BFM 95, was used later to treat 257 patients. The two protocols were similarly successful to treat low and medium risk cases. However, the ALL-BFM 95 protocoll was more efficient to treat high risk patients and resulted in 10% increase in survival. The Western-European results are superior by 10-15% compared to the Hungarian data mainly due to the relatively high proportion of the early death in Hungary. Improvement of these data can only be expected from the development of the diagnostic potentials and from further improvement of treatment of the high isk patients.