One hundred and seventy-nine previously treated children with acute lymphoblastic leukemia in relapse considered not "resistant" to vincristine (VCR) were randomly allocated to receive reinduction therapy with either vindesine (VND) or VCR, in combination with prednisone and L-asparaginase. Complete remission rates were 57% for both regimens and were significantly greater for first relapsers (69%) than for subsequent relapsers (43%). No significant difference in response rates by regimen was observed within relapse groups. Patients treated with VND experienced significantly greater hematologic toxicity. These data suggest that there is no advantage to using VND instead of VCR in standard reinduction therapy for childhood acute lymphoblastic leukemia in relapse.