The main object of the invention is a protection device intended to be mounted on a scalpel (5) provided with a handle (6) and a blade (7), characterized in that the protection device comprises a fixed base (10) comprising a sleeve (11) adapted to be joined to the handle (6) of a scalpel (5), and a movable cap (30) comprising a cap (31) adapted to cover the blade (7) of a scalpel (5) and a mechanical connection (35) connected to the cap (31) to the sleeve (11) so as to allow the displacement of the cap (31), by rotation and translation with respect to the sleeve (11), on one side of the sleeve (11) towards the opposite side of the sleeve (11), while maintaining the connection of the fixed base (10) and of the cap of the mobile assembly (30).
