The aim of this study was to evaluate and compare the clinical characteristics of the B-cell non-Hodgkin lymphoma (NHL) patients and therapeutic efficacy of modified NHL BFM-90 and NHL BFM-95 protocols in the authors' center. From January 1993 to December 2003, 61 newly diagnosed children with B-NHL were enrolled to the study. The patients were stratified by risk factors and treated either with a modified B-NHL BFM-90 or BFM-95 protocols. The use of 1 or 3 g/m(2) of methotrexate instead of 5 g/m(2)/24 h was the only important modification in BFM-90 protocol. Sixty-one children (12 girls, 49 boys) with a median age of 6.5 years (range: 2.5 - 16) were treated in the center. There were 14 patients in stage II, 28 in stage III, and 19 in stage IV. The most common initial primary tumor sites were abdomen, head, and neck. Forty-five patients were treated with modified B-cell BFM-90 and 16 patients were treated with B-cell BFM-95 regimens. The 5-year overall survival (OS) for all patients was 85.8%, and event-free survival (EFS) was 82.8%. The 5-year OS rates in modified BFM-90 and in BFM-95 protocols were 85.2 and 87.5%; the 5-year EFS rates in these 2 protocols were 84.6 and 70%, respectively (p >.05). Factors associated with lower EFS, by univariate analysis were bulky disease, risk groups, and LDH level >= 500 IU/L. By multivariate analysis only LDH level was significant. In, conclusion, the treatment results in this study were similar to those of BFM group.