Introduction: Rituximab (R), a monoclonal antibody to CD20, have been used for treatment of CD20+ B-cell lymphoma. However, R is not commonly used for the treatment of pediatric lymphoma in Korea and there is no previous study for it, because it is not covered by National Health Insurance. The authors evaluated the feasibility of R-combined chemotherapy in B-cell lymphoma of Korean children and adolescents. Patients and methods: Thirteen patients of children, adolescents, and young adults, who were diagnosed with CD20+ B-cell lymphoma and treated with R-based chemotherapy, were analyzed by retrospective review of medical records. Results: Median age of the patients at diagnosis was 12 years (range, 3-25) and 10 were male. Their diagnoses were Burkitt lymphoma in 7 (stage 4 in 4, 3 in 2, and 2 in 1), diffuse large B-cell lymphoma in 2 (both stage 3), primary mediastinal B-cell lymphoma ( PMBCL) in 2 (stage 4 and 2 in each), follicular lymphoma and extranodal MALT lymphoma each in 1 (both stage 2). All of them had LMB96 (10 patients) or CHOP (3)-based chemotherapy, combined with R. Eight of them received R-combined therapy as primary regimen, and 5 as augmented regimen because of poor response to initial chemotherapy. Median number of R given to them was 8 (range, 4-14). During median follow-up of 62 months (range, 2-94), only 2 patients with PMBCL had relapse during R-combined therapy and one had secondary myeloid leukemia without relapse of primary disease. All of them were successfully salvaged. Only 1 of them died of sepsis with neutropenia. Their 5-year event-free and relapse-free survival was 64.7±14.5% and 83.9±10.4%, respectively, and 5-year overall survival was of 91.7±8.0%. There was no infusion-related reaction during a total of 97 infusions of R. Although lymphocyte subset ratio was checked in 3 patients during R-combined therapy showed prominent decrease of B-lymphocyte, there was no severe viral infection during R-combined therapy. One patient with anti-HBc(+) before R had no reactivation of hepatitis B with prophylactic use of entecavir. Conclusion: Despite small number of patients, R is effective for the treatment of CD20+ B-cell lymphoma, except PMBCL, in children and adolescents. No significant toxicity of R was seen. Prospective studies for the evident role of R in treatment of B-cell lymphoma is needed in Korean pediatric patients.