To elucidate the genetic events which may play important roles in hepatocarcinogenesis, we examined every non-acrocentric chromosome arm of 22 hepatocellular carcinomas (HCCs) for loss of heterozygosity (LOH) using 68 highly polymorphic microsatellite markers. Thirty-six (92%) of 39 chromosome arms showed LOH in at least one patient, however 3 chromosome arms, 2p, 2q, and 20q, did not show any LOH. High to moderate frequency of LOH (> 30% of informative cases) was observed at chromosomes 1q (68.1%), 4q (72.7%), 8p (63.6%), 8q (77.3%), 10q (33.3%), 13q (40%), 14q (46.1%), 16q (59.1%), and 17p (46.2%). Among these, LOH on chromosomes 1q and 8q have not been previously identified in HCC. Our results suggest that novel tumor suppressor genes may be involved in the development and progression of HCC.