Ten cases of newly diagnosed pediatric B cell non-Hodgkin's lymphoma or acute lymphoblastic leukemia (B-NHL, stage I & II 6 cases, stage III & IV 2 cases/ALL 2 cases) experienced during the last 7 years (1987-1994) were treated by BLK88 protocol, which consisted of HD-CPM (1,200 mg/m2), and HD-MTX (1,000 mg/m2) with VCR, ADR, and/or AraC combination, and CNS prophylaxis by triple intrathecal injection. The therapy duration was 24 weeks for B-NHL (36 weeks for B-ALL). The results showed that while one of the six cases in stage I & II relapsed, and other 4 cases of stage III & IV B-NHL/ALL remained in complete remission. On the other hand, all of the four cases in stage III & IV in historical controls had relapsed. Neutropenia and liver dysfunction were observed during therapy, but they were tolerable. We conclude that BLK88 is a very useful protocol for B-NHL/ALL in childhood.