A locking device for doors or the like, comprising: a main body fixable to a door; a rotatable handle relative to said main body and sliding axially thereto; a cylinder for locks coupled to the handle and adapted to lock/ unlock the movement of said handle; and a locking element (31, 32) operable in rotation by means of said handle between an open position and an intermediate position and slidable axially with respect to the main body between said intermediate position and a closed position; and a clamping element housed in the main body, that is mechanically connected to the handle and to the locking element (31, 32) and capable of moving the locking element (31,32) from the intermediate position to said closed position as a result of a thrust exerted on the handle; wherein the clamping element comprises a clamping sleeve having a first end, in which a shank is inserted that is capable of axially sliding, which shank is comprised within said handle, and a second opposite end, in which a part of the locking element is inserted, which is capable of axially sliding; wherein said clamping sleeve comprises a first longitudinal portion, which includes at least a first guide slot (61, 62) to which said shank of the handle is solidly constrained, and a second longitudinal portion, which includes at least a second guide slot (63, 64) to which said part of the locking element is solidly constrained; wherein said guide slots (61, 62, 63, 64) are oblique relative to an ideal plane passing through the axis of the sleeve, said first slot (61, 62) being longer of said second slot (63, 64) and also having a direction of inclination opposite to that of the second slot (63, 64) relative to a direction of axial reference. a main body fixable to a door; a rotatable handle relative to said main body and sliding axially thereto; a cylinder for locks coupled to the handle and adapted to lock/ unlock the movement of said handle; and a locking element (31, 32) operable in rotation by means of said handle between an open position and an intermediate position and slidable axially with respect to the main body between said intermediate position and a closed position; and a clamping element housed in the main body, that is mechanically connected to the handle and to the locking element (31, 32) and capable of moving the locking element (31,32) from the intermediate position to said closed position as a result of a thrust exerted on the handle; wherein the clamping element comprises a clamping sleeve having a first end, in which a shank is inserted that is capable of axially sliding, which shank is comprised within said handle, and a second opposite end, in which a part of the locking element is inserted, which is capable of axially sliding; wherein said clamping sleeve comprises a first longitudinal portion, which includes at least a first guide slot (61, 62) to which said shank of the handle is solidly constrained, and a second longitudinal portion, which includes at least a second guide slot (63, 64) to which said part of the locking element is solidly constrained; wherein said guide slots (61, 62, 63, 64) are oblique relative to an ideal plane passing through the axis of the sleeve, said first slot (61, 62) being longer of said second slot (63, 64) and also having a direction of inclination opposite to that of the second slot (63, 64) relative to a direction of axial reference.