Background: Sorafenib (Nexavar®) significantly improved progression-free survival over placebo in global phase 3 study (DECISION), which has led to the approval of sorafenib for the treatment of unresectable differentiated thyroid cancer (DTC) in Japan since June 2014. Although Japanese patients participated in DECISION study, the number of Japanese patients was too small to evaluate safety and feasibility of sorafenib in Japanese DTC patients. Objective: The aim of this surveillance is to investigate the usages and drug related adverse events (DRAEs) of sorafenib in patients with DTC in Japan, and verify the safety profile in clinical practice. Methods: This surveillance including all patients who were treated with sorafenib has been in progress since June 2014. We evaluated the safety profile and the usages based on the data fixed by April 2016 that covers 9-month data after sorafenib initiation with approximately 200 patients. Results: Based on the data collected at 2 months from sorafenib initiation, baseline characteristics of 217 patients as of April 2015 were following; male 41%, average age 69 years old, papillary/follicular/Poorly differentiated 77%/16%/7%, ECOG PS 0-2/3-4 94%/4%, radioactive iodine-refractory 85%; Common DRAEs were hand-foot skin reaction (HFSR) 70%, hypertension 26% and rash 21%. Conclusion: The result from interim analysis at short term follow-up demonstrated that patient characteristics and the safety profile were almost similar to those in DECISION. According to these findings, sorafenib is confirmed to be mostly used properly in clinical practice. The latest data fixed by April 2016 (the data at 9 months after sorafenib initiation, approximately 200 patients) will be presented.