This paper deals with a case of recurrent hepatocellular carcinoma causing needle-tract seeding on the thoracic wall after percutaneous radiofrequency ablation (PRA). The patient was an 83-year-old man who underwent PEI for recurrence in the liver S8 in July 2001 after a posterior segmentectomy of the liver for hepatocellular carcinoma (S6-7) in November 1999. A metastatic lesion 12mm in diameter was detected in the liver S8 in July 2003, and RFA using a cool-tip type electrode was conducted. The PIVKA-II level started to increase and a painless tumor at the punctured site for RFA became apparent in around December 2003, which gradually enlarged. Fluoroscopic ultrasonography visualized tumor vessels and deep stained tumor shadow in the arterial phase, and further stained shadow up to later vascular phase. Needdle-tract seeding on the thoracic wall was thus diagnosed. On April 2, 2004, a removal of the tumor with reconstruction of chest wall was carried out. The histopathological diagnosis was moderately differentiated hepatocellular carcinoma. This paper also presents bibliographical comments on needle-tract seeding after RFA.