Abstract: Objective: To evaluate the efficacy and toxicity of single- agent bendamustine in patients with indolent B- cell non-Hodgkin's lymphoma (NHL) refractory to rituximab.Methods:Between April 2010and April 2013, 100 patients with rituximab-refrac -tory indolent B- cell NHL from 8 institutions were enrolled. Bendamustine was administered at 120 mg/m2 on days 1 and 2 every 21 days for 6- 8 cycles. The primary endpoint was the overall response rate (ORR). The secondary endpoints included disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety. Results:One hundred patients with a median age of56(rang-ing from 28to 74) years were recruited in this clinical study. The total number of chemotherapy was 447 cycles, and the median number was 4 cycles. Ninety-three patients could be evaluated for efficacy. Fifteen patients ( 16.1%) had complete remission (CR), 52(55.9%) had partial remission (PR), 22(23.7%) had stable disease (SD), and4 (4.3%) had progression disease (PD). The ORR and DCR were 72% and 95.7%, respectively. After a median follow-up of26.6 months (ranging from 2 to 48.4 months), 59patients ( 63.4%) had PD. The median PFS was 8.53(95% CI:6.518- 10.542) months, and PFS rate for 1 year was (40.6 ± 5.3)%. Forty-eight patients (48%) had 3/4 grade adverse events, including leucopenia (26% ), neutropenia (24% ), and anemia (11 % ). Conclusion:Single- agent bendamustine produced a high rate of objective responses in patients with rituximab-refractory indolent B-cell NHL and could be one of the new options for second-line treatment of these patients. The most common adverse event is hematologic toxicity.