Between 1969-1973, 75 consecutive children under the age of 15 years with acute lymphoblastic leukemia were treated with a multiple-drug regimen (L-2). Prophylaxis for meningeal leukemia was limited to the repeated intrathecal injections of methotrexate. Seventy-four patients achieved remission; the duration of remissions could be evaluated only for 70. Relapse terminated complete remission within 1-54 months in 21 children. Four of these relapses were confined to the central nervous system. Forty-nine patients continue in complete remission from 23 to 63 months. Chemotherapy has been discontinued in 29 children, and 25 of these remain without evidence of recurrence for 2-27 months posttreatment.