An adjustable bracket for a slide assembly includes a bracket, a support member and an engaging member. The bracket has an aperture and a contact portion. The support member is slidably connected to the bracket and has an opening and a stop portion. The engaging member has a resilient arm and an engaging portion which is connected to the resilient arm and located corresponding to the aperture of the bracket. When the support member slides to a predetermined position, the stop portion is against the contact portion so that the support member is stopped. When the support member slides to an extended position, the opening overlaps the aperture and the engaging portion is inserted into the opening so that the support member is positioned.