We report on our 2-year experience with intraarterial liver therapy with I-131-Lipiodol in patients with hepatocellular carcinoma in Germany. 30 therapies with intraarterial delivery of I-131-labeled Lipiodol were performed in 14 patients with hepatocellular carcinoma (HCC) with or without portal vein thrombosis during hepatic angiography. The patients were monitored for 1) distribution of Lipiodol by CT, 2) distribution of applied activity by planar scintigraphy and SPECT, and 3) tumor response by CT, MRT and 18-FDG-PET. In 5 patients the tumor size was reduced after the first treatment (responder). Eight patients, primarily with big tumors (> 7 cm), had stable (4) or progressive disease (4), and 1 patient died because of renal failure. CT and SPECT showed pronounced I-131-lipiodol accumulation in the tumor tissue in all patients with variable distribution patterns. One patient had an acute pancreatitis like syndrome together with elevation of liver enzymes, probably due to arterial spasm. 9 patients had transient and mild symptoms in the upper abdomen, fever to 40 degrees C, and a leukocytosis. Two patients had a transient mild elevation of pancreatic enzymes. All patients had a transient rise in liver enzymes. In conclusion, therapeutic efficacy was dependent on the tumor mass. Side effects due to the radiopharmaceutical were tolerable, and other side effects may result from the angiography procedure related manipulations. These results are encouraging for tumors up to a moderate mass.