Gene therapy using an adenoviral vector expressing tumor necrosis factor-alpha (TNF-α) is a new therapeutic approach for pancreatic cancer. However, the efficacy of TNF-α is limited, because it activates nuclear factor-κB (NF-κB). We investigated the combined use of AxCAhTNF-α, adenoviral vector-expressing human TNF-α, and nafamostat mesilate, a serine-protease inhibitor, a NF-κB inhibitor, using pancreatic cancer in mice. In vitro, nafamostat mesilate inhibited TNF-α-induced NF-κB activation and enhanced TNF-α-induced apoptosis in human cancer cell line (MIAPaCa-2). In vivo, we assessed combination treatment of AxCAhTNF-α and nafamostat mesilate using xenograft models in nude mice by subcutaneous injection of MIAPaCa-2. When the implanted tumor size reached 8.0mm, TNF-α group (n=12), was injected AxCAhTNF-α intra-tumorally once a week, while combination group (n=12), was injected AxCAhTNF-α intra-tumorally once a week and nafamostat mesilate intraperitoneally thrice a week. In combination group, tumor growth was significantly slower, and the number of apoptosis cells was significantly greater than those in AxCAhTNF-α group (p<0.05). In conclusion, adenovirus vector-mediated TNF-α gene therapy combined with nafamostat mesilate was effective for pancreatic cancer in mice.