Variations in the activity of protein kinase C (PKC) have been observed in different types of tumors. Although these inconsistent findings may be attributed to the alterations of individual PKC isoforms, the effects of general anesthetic may not be neglected. In this study, biopsies and surgical specimens were obtained from patients with HCC, and the levels of PKCalpha were analyzed by immunohistochemistry. PKCalpha expression in biopsies was mainly revealed on the cell membrane of hepatocytes whereas that in the surgical specimens was in the cytosol and on the membrane. In both types of specimens, the PKCalpha level in HCC was significantly higher than that in the adjacent non-tumorous tissue. Moreover, the level of PKCalpha in biopsies was significantly higher than that in surgical specimens of the corresponding tissue type. These findings suggested that general anesthetics may significantly affect the expression of PKCalpha, and the effects of anesthetics should not be neglected in observations which were made only based on surgical specimens.