A total of 62 patients with standard-risk acute lymphoblastic leukemia received three-drug induction consisting of vincristine, prednisolone, and L-asparaginase (l-Asp) followed by consolidation therapy with intermediate-dose methotrexate (MTX), intrathecal MTX, and 18 Gy of cranial irradiation. Maintenance therapy consisting of 6 drugs including daunorubicin (DNR, 450 mg/m2 in total) was continued for 3 years. Patients were randomized and half of them received weekly l-Asp during maintenance therapy as a late intensification. Complete remission (CR) was achieved in 61/62 (98.4%), and 11 of 61 patients relapsed. At 10 years, the event-free survival (EFS) was 80.6 +/- 5.0% and overall survival was 88.7 +/- 4.0%; median follow-up time was 9.3 years. The 10-year EFS of patients with additional l-Asp (84.8 +/- 6.2%) was superior to that without l-Asp (75.9 +/- 7.9%), although it was not statistically significant. No patients who received a full dose of DNR and maintained CR developed heart failure, although the shortening fraction decreased from 41.0% at diagnosis to 35.2% (median). The protocol AL841 provided good long-term disease control without severe late cardiac dysfunction.