OBJECTIVE To assess the efficacy of a chemotherapy-only regimen in pediatric patients with disseminated non-lymphoblastic lymphoma and acute B-cell leukemia (B-ALL). METHODS Sixty-eight eligible patients with previously untreated disseminated non-lymphoblastic lymphoma were enrolled on a Childrens Cancer Group study. Therapy included cycles of chemotherapy, systemic and intrathecal (IT), ever 3 weeks for a total maximal duration of 57 weeks. Fifty-five patients had small non-cleaved cell lymphoma (SNCCL) and 13 had diffuse large cell lymphoma (DLCL). Forty-seven were stage III, six were stage IV, and 15 had B-ALL; 13 had central nervous system (CNS) involvement. RESULTS Four year event-free survival (EFS) was 53% (SE +/- 12%). Stage III SNCCL patients with LDH < 500 IU/L achieved an improved EFS compared to other SNCCL patients (86% vs. 42% 4 year EFS, P = .072). The primary site of failure for advanced stage SNCCL patients was the CNS. All Ki-1-positive DLCL patients relapsed. Patterns of failure, time to relapse, and outcome following relapse differed between SNCCL and DLCL patients. CONCLUSIONS Advanced stage SNCCL requires better CNS-directed chemotherapy to reduce the CNS failure rate; however, the achievement of durable disease-free survival in four of 11 patients with CNS disease without use of cranial irradiation suggests merit for further evaluation of chemotherapy-only strategies. DLCL patients do not need intensive CNS-directed chemotherapy.