Background: Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy (R-CHOP) has improved survival in patients with diffuse large B-cell lymphoma. Purpose: To assess the clinical outcome of chemotherapy with R-CHOP in some types of B-cell lymphoma. Patients and methods: descriptive study of 31 patients with confirmed B-cell lymphoma, CD20+ and treated with R-CHOP chemotherapy in National Institute of Hematology and Blood Transfusion from 1/2009 to 6/2011. Results: Complete response rate after 3 cycles was 80,5 percent and 6 cycles was 87,1 percent. The main side effect was neutropenia (54,8 percent). Conclusion: Addition of rituximab to standard CHOP chemotherapy has significantly complete response rates in B-cell lymphoma.