Despite the clear visualization of a hepatic tumor on various imaging modalities, no tumor was able to be identified by intraoperative ultrasonography and in the resected material in a 38-year-old man. The patient was incidentally found to have a hepatic tumor 1.5 cm in diameter in the S6 of the liver on CT scanning. In the liver surrounding the tumor, diffuse fatty infiltration was seen, and the tumor was revealed as strong echoes on ultrasonography, hypoattenuation area on precontrast CT, hyperintensity on T1-weighted magnetic resonounce imaging (MRI), and isointensity on T2-weighted magnetic resonounce imaging (MRI), and isointensity on T2-weighted images. On angio-CT, the portal blood flow in the tumor was equipotent to that of surrounding liver, and a decrease in arterial blood flow was observed. With a preoperative diagnosis of well differentiated hepatocellular carcinoma, the patient was operated on. With intraoperative ultrasonography as well as on a section of the resected material, no tumor was demonstrated. Histopathologically, it was moderate degree of fatty droplets and no findings suggestive of tumor image were noted.