We report on a 63-year-old man with a history of hepatitis B virus-related hepatocellular carcinoma with a thrombus extending into the inferior vena cava, who received image-guided stereotactic body radiation therapy (SBRT) with helical tomotherapy, followed by sorafenib. A total tumor dose of 48 Gy was delivered by 6 fractions within 2 weeks. The tumor responded dramatically, and the patient tolerated the courses well. Ten days after SBRT, sorafenib (200 mg), at 1.5 tablets twice a day, was prescribed. One week later, grade 2 recall radiation dermatitis subsequently developed in the previous SBRT off-target area. SBRT followed by sorafenib for the treatment of a portal vein thrombosis provided effective results, but the potential risk of enhanced adverse effects between radiation and sorafenib should be considered with caution, especially under a SBRT scheme.