To investigate the polycyclic aromatic hydrocarbon (PAH) effect on fertilization of the Pacific oyster, Crassostrea gigas, we exposed the adult brood stocks to PAHs (200 ppb) for 30 days as the treated (E group) with a nonexposed group as the control (C group). In addition, each subset of the gametes from both groups was further exposed to graded level of PAHs (0, 50, 100, and 200 ppb). Motile sperm and linearity were significantly affected by parental exposure, whereas straight line velocity (VSL) and curvilinear velocity (VCL) were affected by both of parental and larval exposure to PAHs. Fertilization and larval development were also affected by parental exposure. Our result suggests that fertilization capability and larval development are adversely affected by parental exposure whereas sperm movement was more vulnerable to larval exposure. In the brood stock contaminated by PAHs, larval development was also vulnerable to larval exposure to PAHs.