The invention relates to an adjustment device for manual cutting tools. The cutting tool for which the device is intended preferably takes the form of a pruning shears having two arms (2) with the respective cutting blades (3 and 4) thereof hinged to one another by a transverse bolt (6) forming the main element of the device. The corresponding nut (7) for locking the hinge bolt (6) is provided with a transverse hole (11) into which a locking screw (10) is screwed, thereby enabling the hinge to be adjusted. The nut (7) and the locking screw (10) are positioned in a recess in the cutting blade (4) such that the nut (7) cannot rotate when the bolt (6) is being manipulated using a protrusion (14) of the nut (7) housed in a cavity (15) in the cutting blade (4). The through-hole provided in the cutting blade (3) for the bolt (6) includes a bush (13) which enables the bolt (6) to be better adjusted in the hole.
