A stabilizer assembly for laterally supporting a construction vehicle of the type having a material handling implement. The preferred embodiments of the stabilizer assembly permit selective positioning of the outboard ends of the stabilizer arms over a wide range of positions from a position immediately adjacent the vehicle wheels and near the longitudinal center line of the vehicle frame to a position substantially outside of the wheels and farther from the longitudinal center line of the vehicle frame. The inboard ends of the stabilizer arms are pivotally secured to a stabilizer anchor which is transversely slidable relative to the vehicle frame on either side of the center line thereof. Various means are disclosed for positioning of the stabilizer anchor relative to the vehicle frame and for retaining the stabilizer anchor in such position.