Abstract: A safety device for lawn mowers includes an elongated frame assembly having a pair of laterally spaced leg elements connected by a bight section. A plurality of ground anchoring elements depend from the bight section and are adapted to be selectively affixed in the ground to prevent rolling of the mower. The device includes clamping plates for fixedly securing the assembly to the handle of a lawn mower in angular relation thereto such that the ground anchoring elements are out of contact with the ground during normal operation of the mower and the mower is pivotable upon its rear wheels in an emergency to thereby shift said leg elements into a position substantially perpendicular to the ground and drive the ground anchoring elements into the ground to prevent rolling of the mower.