A seat slide apparatus for a vehicle includes a first rail adapted to be securely mounted on one of a vehicle floor and a seat, a second rail adapted to be securely mounted on the other of the vehicle floor and the seat and movably assembled relative to the first rail, a first bent portion formed at the first rail, a pair of second bent portions respectively formed at the second rail at longitudinal sides of the first bent portion of the first rail so as to contact the first bent portion to restrict further relative movement of the first and second rail, and a relief portion provided at one of the first and second rails so as to face one of the second and first bent portions, respectively.