Background: Trifluridine/tipiracil (TAS-102) is an oral combination therapy approved for the treatment of patients with metastatic colorectal cancer (mCRC). Phase 1/2 C-TASK FORCE study of TAS-102 plus bevacizumab for patients with refractory mCRC demonstrated a promising efficacy results with mild toxicity profile (Kuboki Y, et al. Lancet Oncology, 2017). The retrospective single-institutional study is aiming to investigate safety of TAS-102 plus bevacizumab for patients with refractory mCRC in real-world clinical practice. Methods:_MCRC patients who were refractory or intolerant to a fluoropyrimidine, irinotecan, oxaliplatin, anti-VEGF therapy, and anti-EGFR therapy (if wild-type RAS) and consecutively received TAS-102 plus bevacizumab between January 2016 and June 2017, were analyzed. Adverse events (AEs) were assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 4.0. Results: A total of 33 patients were identified for safety analysis. Patient characteristics were as follows; male/female, 19/14; median age, 59.0 (range 38-81); ECOG Performance Status of 0/1, 21/12; and All wild/ RAS mutant/ BRAF mutant/ unknown, 16/15/1/1. Six patients had received prior regorafenib. The relative dose intensities of TAS-102 and bevacizumab were 87% and 79%, respectively. Grade 3 or higher hematological and non-hematological AEs were follows; leucopenia, 33%; neutropenia, 42%; anemia, 9%; and proteinuria, 12%. There were no febrile neutropenia or treatment-related death. G-CSF was given in 8 patients (24%), while intravenous antibiotics was in one patient. There were four patients with emergency admission, and out of these, the two patients had intestinal perforation, and perianal abscess, which were regarded as treatment-associated; ultimately these AEs were fully recovered. Conclusions: Our findings suggested safety for TAS-102 plus bevacizumab combination in real-world clinical practice is consistent with those in clinical trial setting.