This study aimed to evaluate and compare the biodistribution properties of three transarterial Lipiodol-based therapeutic regimens in human hepatocellular carcinoma (HCC). In this prospective study with 13 patients randomly allocated to one of three study groups, each of the patients received transcatheter intra-arterial administration into a solitary HCC with one of three different Lipiodol-based formulations: Lipiodol-ethanol mixture (LEM; Group A), Lipiodol alone (Group B), and Lipiodol and gelatin pledgets (Group C). With the use of radioactive iodine-131-labeled Lipiodol, each group was assessed for (1) pattern of Lipiodol accumulation in the lungs within the first 2 weeks as evaluated by single-photon emission computed tomography and (2) decomposition of Lipiodol formulation within the first 2 weeks as evaluated by radioactivity detected in peripheral blood and urine. The degree of Lipiodol retention in the tumor within the first 4 weeks was evaluated with CT. No statistically significant difference in Lipiodol accumulation in the lungs was detected among the three groups. However, the peak accumulation in the lungs was delayed 3 days for Group A compared to Groups B and C. The degree of Lipiodol retention within the tumor in Group A was significantly greater than that in Groups B and C on day 14 (p = 0.014) and day 28 (p = 0.013). This study showed that LEM is associated with a greater embolic effect in intrahepatic HCC at 4 weeks, and a comparable degree of lung shunting and decomposition rates, compared with ethanol-free Lipiodol formulations.