Sixty-two adult patients with acute lymphoblastic leukemia (ALL) were treated with an induction regimen including vincristine, daunorubicin and prednisone (VDP) followed by CNS prophylaxis. Forty-five patients (72.5%) achieved complete remission (CR). The CR were maintained with daily 6-MP and weekly MTX. Monthly reinduction cycles with vincristine and prednisone (plus daunorubicin every three courses) were also given. Median duration of CR was 10.4 months. Overall survival was 17.4 months. The remission rate and length of CR were studied in relation to the clinical and hematological features present at diagnosis. CR rate was adversely influenced by age only over 40 and by tumoral presentation. The length of remission was negatively influenced by tumoral presentation, CNS involvement, high circulating blast count, L2 and L3 cytology, and T or B immunological phenotype. Multiple regression analysis confirmed the weight of FAB morphology in determining the length of remission. Among L2 adult patients, tumoral presentation appears to be the major unfavourable prognostic factor.