In patients with hepatocellular carcinoma (HCC), natural killer (NK) cell activity decreases significantly, and the reduced activity may be associated with the progression of HCC. In this study we evaluated the effects of pulsing with interleukin (IL)-2 and/or IL-12 on the activation of freshly isolated peripheral blood lymphocytes (PBL) derived from patients with HCC. PBL obtained from 9 HCC patients, 4 liver cirrhosis patients, and 9 normal subjects were cultured in the presence of IL-2 and/or IL-12. After 24 h of incubation, the levels of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha presented in the supernatants were determined by enzyme-linked immunosorbent assay (ELISA). The IFN-gamma and TNF-alpha production of PBL pulsed by a combination of IL-2 and IL-12 was significantly higher than those of PBL stimulated by either IL-2 or IL-12 alone. The mRNA encoding perforin, granzyme B, as well as IFN-gamma and TNF-alpha, were markedly enhanced in PBL stimulated with a combination of IL-12 and IL-2. The pulsing procedure of IL-12 in combination with IL-2 resulted in the increase of IFN-gamma and TNF-alpha, and the expression of perforin and granzyme B mRNA in PBL obtained from HCC patients, as well as in those obtained from normal subjects. These results indicate that adoptive immunotherapy based on PBL pulsed with a combination of IL-2 and IL-12 may be a promising adjunctive strategy for HCC treatment.