Background: Combination chemotherapy of capecitabine plus oxaliplatin (XELOX) with bevacizumab is commonly used as standard chemotherapy for metastatic colorectal cancer (mCRC). A previous meta-analysis showed that there was no difference between two age groups of <65 years and ≥65 years on overall survival (OS) after treatment with chemotherapy with bevacizumab. However, the safety and efficacy of XELOX with bevacizumab in elderly patients (pts) ≥75 years with mCRC remain unclear. Methods: This study was an open-label multicentre phase II study to evaluate the efficacy and safety of XELOX with bevacizumab in pts ≥75 years with metastatic CRC. The primary objective was to assess progression-free survival (PFS). The secondary endpoints were the safety, response rate (RR), time to treatment-failure (TTF) and OS. Results: 36 pts were enrolled. Pts characteristics were; median age 78 (range 75-86); male/female, 21/15; ECOG performance status 0/1, 30/6; colon/rectum 24/12, creatinine clearance (CCr) 60.2 ml/min (range 32.6-84.6). Median follow-up period was 220 days. RR was 55.6% and median TTF was 209 days. The median PFS and median OS are not reached. Grade 3 or 4 adverse events (AEs) were reported in 22 pts (62.8%). Common grade 3 or 4 AEs were hypertension (11.4%), leukopenia (20.0%), peripheral sensory neuropathy (14.3%), hand foot syndrome (8.6%), and fatigue (8.6%). Examining the relationship between renal function (CCr) and AEs, the incidence of Grade 3 or 4 AEs in the lower CCr group was significantly higher than that in the higher CCr group (61.6% vs. 47.8%; p=0.013); hematological toxicities (87.5% vs. 14.8%; p=0.0003) and non-hematological toxicities (61.5% vs. 11.1%; p=0.018). Conclusions: XELOX with bevacizumab is safely administered in elderly patients ≥75 years. Renal function (CCr) could be a good predictive marker for grade 3 or 4 AEs. Clinical trial information: UMIN000003500.