The influence of rituximab therapy on prognosis and hepatic toxicity (HT) in patients with hepatitis C virus (HCV)-positive diffuse large B-cell lymphoma (DLBCL) is unclear. Thus, we assessed HT and clinical outcome in patients with DLBCL and HCV infection who received rituximab-containing immunochemotherapy. We carried out a prospective analysis on a total of 280 HCV-positive patients with DLBCL, 200 of whom received chemotherapy plus rituximab (R-CHT), 80 received chemotherapy (CHT)-only. Survival outcomes and HT were compared according to rituximab administration. The median follow-up was 41 months. Addition of rituximab did not significantly affect prognosis (median progression-free survival, 40 vs 35 months, P = 0.26; median overall survival, 51 vs 43 months P = 0.09). Of 200 patients who received rituximab, 53 (26.5 %) had severe HT (grade 3-4), compared with 11 of 80 (13.75 %) patients who received rituximab-free regimens (P = 0.033). Among patients treated with rituximab, 50 patients (25 %) did not complete planned course of therapy, 14 patients because of hepatic toxicity and 36 patients because of progressive disease. Pretreatment liver function impairment was predictive of severe HT. These results raise concerns regarding the routine use of rituximab with chemotherapy in individuals with HCV-positive DLBCL. However, more studies are warranted before a definitive conclusion can be made.