Abstract: A hydraulically-actuated bedknife alignment and positioning mechanism which uses the hydraulic power source to precisely adjust the distance between the blade of a reel-type lawn mower and the bedknife for proper cutting action. The system includes a source of hydraulic fluid under pressure, a hydraulic cylinder (mounted to the frame of the mower) which houses a piston connected by a linkage arm to the bedknife that is biased relative to the reel blade and attached pivotally to the frame. During adjustment, the cylinder is pressurized, forcing the piston to move the bedknife into contact with the blades of the mower. When the hydraulic pressure is removed, the biasing force pushes the bedknife away from the reel blade, but a hydraulic locking valve in the actuating cylinder line limits precisely how far the bedknife is biased away from the reel blade before sealing shut, effecting proper distance setting. The hydraulic adjustment may be remotely actuated by the operator of the mower.