Background/Aims: Computed tomography during arterial portography (CTAP), computed tomo-graphy during hepatic arteriography (CTHA) and Lipiodol CT are highly sensitive methods to detec intrahepatic tumor. Their sensitivity and accuracy are over 90% and 85%, respectively. We evaluated the usefulness of CTAP, CTHA and Lipiodol CT as a preoperative examination. Methods: For eighty two patients with hepatocellular carcinoma which were considered as the resectable on spiral CT and angiogram, CTAP and CTHA were performed. The additional nodules on CTAP and CTHA were confirmed by Lipiodol CT. Results: CTAP and CTHA could find additional nodules in 28% of the patients. The treatment plan was changed from surgical to nonsurgical method in 12% of the patients The larger tumor nodules were on the spiral CT, the more additional tumor nodules were found on CTAP and CTHA (p=0.03). The probability of finding additional nodules on CTAP and CTHA is no related with the counts of tumor nodules on the spiral CT (p=0.84). CTAP and CTHA could find additional nodules in 6 cases of 27 cases who underwent Lipiodol CT. The treatment plan was changed to nonsurgical treatment in 3 cases by the results of CTAP and CTHA. Conculusions: We concluded that CTAP, CTHA and Lipiodol CT are useful in avoiding unnecessory operation. (Kor J Gastroenterol 1998;32:740 - 748)