OBJECTIVE: To investigate the expression status of Sonic Hedgehog signaling genes and molecules in human hepatocellular carcinomas(HCC), and to explore the relationship between these genes and clinical prognosis. METHODS: HCC tissue and adjacent normal tissue from 29 HCC patients were assayed for the expression of hedgehog signaling genes by reverse transcription-polymerase chain reaction chain reaction (RT-PCR) techniques and for the expression of hedgehog signaling molecules by immunohistochemistry. The expressions of Shh, Ptch, Smoh, Gli-1 mRNA were assayed as well as Shh, Ptch proteins in 29 cases of HCC and in 29 liver tissues adjacent to the tumor. RESULTS: Expression of Shh mRNA was detectable in about 51% of HCCs examined. Consistent with this, hedgehog target genes Ptch, Smoh and Gli-1 mRNA were expressed in over 68%, 48% and 62% of the tumors, respectively, and the expressions of Shh and Ptch proteins in HCC tumor tissues correlated with those of Shh and Ptch mRNA in tumor tissues (P=0.041 and P=0.035). This suggested that the hedgehog pathway was frequently activated in HCCs. The simultaneous expression of Gli-1 in HCC and liver tissues adjacent to the tumor had significantly relationship with poor prognosis. CONCLUSION: Hedgehog signaling activation is an important event for development of human HCCs. It also suggests that markers for hedgehog signaling activation may be useful for the determination of prognosis.