The safety and efficacy of rituximab with CODOX-M/IVAC (cyclophosphamide, doxorubicin, vincristine, methotrexate/ifosfamide, etoposide, high dose cytarabine) was retrospectively analysed in 23 patients with non-human immunodeficiency virus-related B-cell non-Hodgkin lymphoma with proliferation index >95% [14 with classical Burkitt lymphoma (BL), five with B-cell lymphoma unclassifiable, with features intermediate between diffuse large B cell lymphoma (DLBCL) and BL, and four with DLBCL]. Six (26%) low-risk (LR) patients received three cycles of CODOX-M and 17 (74%) high-risk (HR) cases were assigned to four cycles of alternating CODOX-M/IVAC. Rituximab 375 mg/m2 was infused on days 1 and 10 of each cycle. Toxicity was comparable to that reported with CODOX-M/IVAC, with no treatment-related death. Two patients developed grade 3 rituximab-induced delayed neutropenia, with no adverse outcome. After completing treatment, 83% LR patients and 71% HR patients achieved CR by positron emission tomography–computerized tomography (PET–CT). Three (13%) patients received salvage treatment. At a median follow-up of 34 months (range = 18–75), 19 (83%) patients (100% LR and 74% HR) were alive, including one case undergoing salvage for late relapse. Four HR patients (17%) had died, three from primary progressive disease and one from treatment-refractory relapse 2 months after achieving CR. These results with R-CODOX-M/R-IVAC compare favourably with existing data using CODOX-M/IVAC and warrant further prospective studies. The potential pitfalls of PET–CT to assess response are highlighted.