Although a metastasis to the gastrointestinal tract (GI) is rare in patients with hepatocellular carcinoma (HCC), it can occur by hematogenous or lymphatic spread, or by direct invasion of a tumor. A 61-year old woman who had a progressing large primary liver cancer presented with upper gastrointestinal (UGI) bleeding. UGI endoscopy showed a large duodenal submucosal tumor-like mass with a central ulcer and adherent blood clots. Endoscopic biopsy and coagulation using argon plasma probe were performed. The microscopic examination revealed a HCC. We report this unusual case of HCC with direct invasion of the duodenum. (Korean J Gastrointest Endosc 2006;33:298302)