Second remission induction rates for vincristine and prednisone alone (VP) and vincristine, L-asparaginase, and prednisone (VLP) are compared for children with acute lymphocytic leukemia. No evidence of a significant difference between the second induction complete remission rate for VP (78.6%) and VLP (73.7%) was found. Duration of first remission and prognostic group at initial diagnosis (defined on the basis of age and white blood count at initial diagnosis) are shown to be significant prognostic factors for second remission induction; and three second remission induction risk groups are defined on the basis of these two factors. Periodic reinforcement with prednisone in first remission does not appear to lower second induction complete response (CR) rates for VP. There was no evidence of a significant difference in the frequency of occurrence of severe toxicity between the VP and VLP regimens.