A hydraulic floor jack includes a rectangular frame with side flanges and having an extended control handle with a control lever. A pivotal lifting mechanism is mounted on the frame including a pair of parallel lift arms having rearward ends interconnected by a lateral push bar. The forward ends of the lift arms are pivotable upward for lifting a load as the push bar is translated forward within a pair of longitudinal "U" channel tracks attached to the inner side flanges. A hydraulic cylinder is secured at the rearward end of the frame for pushing the lateral push bar forward, and for releasing the lateral push bar rearward along the tracks. The safety mechanism includes a toothed rack bar secured on the vertical wall of the tracks. The lateral push bar has bore holes in the ends thereof. A cylindrical dog is slidably supported within each of the bore holes and has a distal end that is extendable for engaging a tooth of the rack bar. The dogs are biased into the extended position and includes linkage for releasing each dog from the rack bar by actuating the control lever