Specific chromosome aberrations are frequently detected during the development of hepatocellular carcinoma. Molecular cytogenetic approaches such as comparative genomic hybridization and loss of heterozygosity analyses have provided fruitful information on changes in HCC cases at the genomic level. Mapping of chromosome gains and losses have frequently resulted in the identification of oncogenes and tumor suppressors, respectively. In this review, we summarize some frequently detected chromosomal aberrations reported for hepatocellular carcinoma cases using comparative genomic hybridization and loss of heterozygosity studies. Focus will be on gains of 1q, 8q, and 20q, and losses of 4q,8p, 13q, 16q, and 17p. We then examine the candidate oncogenes and tumor suppressors located within these regions, and explore their possible functions in hepatocarcinogenesis. Finally, the impact of microarray-based screening platforms will be discussed.