Prostate cancer is the second most frequently diagnosed cancer among men worldwide and a novel treatment for the disease is required. Replication-deficient virus particles, hemagglutinating virus of Japan envelope (HVJ-E), has cytotoxicity to cancer cells. To enhance the therapeutic effect of HVJ-E by photodynamic therapy (PDT) as a trigger of HVJ-E’s anti-tumor effect, talaporfin sodium (Laserphyrin) used for PDT was encapsulated into HVJ-E to produce a novel photosensitizing drug, named Laserphyrin ®-HVJ-E, and its therapeutic effect for prostate cancer cells (PC-3) was evaluated. As the results, direct cytotoxicities of HVJ-E and Laserphyrin ®-HVJ-E for PC-3 after an administration time of 48 h were almost the same. Cell survival rates of PC-3, which were irradiated 2 h after administration of Laserphyrin ®-HVJ-E, were about 7.8%. Although further study is needed to find an optimal PDT condition, these results suggest that Laserphyrin ®-HVJ-E is useful for treatment of prostate cancer due to the combination of cytotoxicities of HVJ-E and PDT.