A drawer slide assembly includes first and second rails, a drawer frame member, a mounting device, and an inserting member. The second rail is longitudinally movable with respect to the first rail. The drawer frame member is connected to the second rail and includes a carrier and a drawer sidewall connected to the carrier. The mounting device is connected to the drawer frame member and/or the second rail and includes an engaging member and a guiding member. The engaging member has an engaging portion corresponding to the guiding member. The inserting member corresponds to the guiding member and can be inserted thereinto to displace the engaging member to an engaged position and, by engaging with the engaging portion, be mounted to the mounting device.