Background: Aggressive mature B-cell non-Hodgkin lymphoma (B-NHL) is the most common non-Hodgkin lymphoma in children. The outcome of chemotherapy for B-NHL has improved over decades. Methods: We reviewed 82 children and adolescents with B-NHL diagnosed at Asan Medical Center between 1993 and 2020. The D-COMP/COMP (daunomycin–cyclophosphamide, doxorubicin, vincristine, and prednisolone), Pediatric Oncology Group (POG)-9219/9315/ 9317, R-CHOP/CHOP (rituximab–cyclophosphamide, doxorubicin, vincristine, and prednisolone), and Lymphomes Malins B 89 (LMB89)/LMB96 regimens were administered. In 2018, rituximab was added to the LMB protocol (R-LMB) for advanced-staged Burkitt lymphoma (BL). The patients’ clinical features and treatment outcomes were retrospectively analyzed. Results: The most common subtype was BL (61%), followed by diffuse large B-cell lymphoma (DLBCL) (35%). The median age was 7.8 (range, 1.3‒16.4) years, and the most frequently used regimen was French‒American‒British (FAB)/LMB96 (58 patients, 70.7%). The 5-year overall survival (OS) and event-free survival (EFS) rates were 92.5% and 85.7%, respectively. The EFS rates of patients with BL and DLBCL were 90.0% and 79.3%, respectively. Among the FAB/LMB risk groups, group C (85.7%) had a significantly lower 5-year OS (P =0.037). Eleven events occurred (6 relapses, 3 deaths, and 2 secondary malignancies) during the median follow-up of 7.1 (range, 3.7‒118.5) months. Two patients treated with R-LMB had good outcomes without complications. Conclusion Various treatment regimens have favorable outcomes in pediatric patients with B-NHL.However, further studies are needed to improve survival in high-risk patients. In addition, careful monitoring for acute toxicity or secondary malignancy due to intensive multidrug chemotherapy is required.