The invention discloses a tailgate structure. Even when a heavy load is applied to a tailgate of resin, deformation of the tailgate is inhibited. A tailgate (16) includes a window frame portion (30) of resin forming a window opening portion (28). The window frame portion (30) includes a bottom wall (38) located on the vehicle interior side, and an outer sidewall (40) and an inner sidewall (42) each of which extending from the corresponding either one end of the bottom wall (38). The tailgate (16) connects the exterior ends of an outer sidewall (40) and an inner sidewall (42) to form a closed cross-section (72), and includes a hinge reinforcement member (34) fitted to a hinge mechanism (18). The hinge reinforcement member (18) includes an outer sidewall reinforcement portion (68) along the outer sidewall (40). The hinge member (48) is fastened to the outer sidewall reinforcement portion (68) and the outer sidewall (40) together by a connection bolt (64) and a nut (65).