To assess the efficacy and safety of ramucirumab in combination with FOLFIRI in patients with unresectable metastatic colorectal cancer under clinical practice in Japan, we reviewed manuscripts reporting clinical research, including case reports, of Japanese patients with FOLFIRI plus ramucirumab therapy published starting from 2016, when ramucirumab was approved as a treatment for metastatic colorectal cancer in Japan, to June 2020. We also reviewed an interim report of post-marketing surveillance study. The efficacy of ramucirumab in combination with FOLFIRI including irinotecan 150 mg/m2, which is the recommended dose in Japan and is used as initial dose in Japanese clinical practice, was similar to that of the global, phase 3 RAISE study with irinotecan 180 mg/m2. The desirable effect of FOLFIRI plus ramucirumab was observed in patients with wild-type RAS, primary tumors on the left sides(descending, sigmoid, or rectum colons), or who received anti-epidermal growth factor receptor agents, including panitumumab or cetuximab, as previous treatment. Also, the effectiveness of FOLFIRI plus ramucirumab as a late-line treatment was suggested. Several patients were reported to have nephrosis syndrome after starting ramucirumab, but they recovered with discontinuation of ramucirumab and appropriate treatment. No new safety concerns were observed from the literature or the interim report of post-marketing surveillance study.