We evaluated the role of rituximab during remission induction chemotherapy in relapsed aggressive CD20+ non-Hodgkin lymphoma. Of 239 patients, 225 were evaluable for analysis. Randomized to DHAP (cisplatin-cytarabine-dexamethasone)-VIM (etoposide-ifosfamide-methotrexate)-DHAP (cisplatin-cytarabine-dexamethasone) chemotherapy with rituximab (R; R-DHAP arm) were 119 patients (113 evaluable) and to chemotherapy without rituximab (DHAP arm) 120 patients (112 evaluable). Patients in complete remission (CR) and partial remission (PR) after 2 chemotherapy courses were eligible for autologous stem-cell transplantation. After the second chemotherapy cycle, 75% of the patients in the R-DHAP arm had responsive disease (CR or PR) versus 54% in the DHAP arm (P=.01). With a median follow-up of 24 months, there was a significant difference in failure-free survival (FFS24; 50% vs 24% vs, P<.001), and progression free survival (PFS24; 52% vs 31% P<.002) in favor of the R-DHAP arm. Cox-regression analysis demonstrated a significant effect of rituximab treatment on FFS24 (HR 0.41, 95% confidence interval [CI] 0.29-0.57 versus 0.51, 95% CI 0.37-0.70) and overall-survival (OS24: HR 0.60 [0.41-0.89] vs 0.76 [0.52-1.10]) when adjusted for time since upfront treatment, age, World Health Organization performance status, and secondary age-adjusted international prognostic index. These results demonstrate improved FFS and PFS for relapsed aggressive B-cell NHL if rituximab is added to the re-induction chemotherapy regimen.