In this national study, we have evaluated a new intensive chemotherapy protocol for adult patients with untreated acute lymphoblastic leukaemia (ALL). One hundred and fifty-three patients with median age 42 years received induction therapy with high-dose cytarabine (Ara-C), cyclophosphamide, daunorubicin, vincristine and betamethasone. A high complete remission (CR) rate (90%) was achieved in patients < 60 years compared with 70% in patients > 60 years (P = 0.004). The estimated 3 year overall survival for all patients was 29% (CI 21-36%) and the estimated continuous complete remission (CCR) at 3 years for the patients achieving CR according to the protocol was 36% (CI 27-45%). A favourable pretreatment characteristic was pre-B phenotype, especially for patients < 40 years without any high-risk factor, with an estimated CCR at 3 years of 62% (CI 41-82%). Stem cell transplantation (SCT) as post-remission therapy, mainly for high-risk patients, gave an estimated 3 year disease free survival (DFS) after SCT of 39% (CI 24-54%). No significant differences in DFS could be found between autologous, related or unrelated donor transplantation. We conclude that this intensive protocol resulted in a high CR rate combined with acceptable side-effects and a favourable CCR for patients with pre-B ALL.