A damping or return device for sliding door leaves (2a, 2b), particularly for furniture, the device being constituted by: a rectilinear hollow body (8a, 8b) made of plastic material wherein said rectilinear hollow body (8a, 8b) accommodates a bidirectional shock absorber; a profile (31a, 31b) that is mountable with the top of said piece of furniture; wherein said rectilinear hollow body (8a, 8b) is slideably associated with said profile (31a, 31b) and can be coupled automatically and with a snap action to an entrainer (10a, 10b) of said device that is fixable to one of said door leaves (2a, 2b) by way of a carriage (11a, 11b, 14a, 14b) of said device; and a first or a second stroke limiting pivot (25a, 25b, 26a, 26b) wherein said rectilinear hollow body (8a, 8b) interacts selectively with the first or the second stroke limiting pivot (25a, 25b, 26a, 26b) which are associated with said profile (31a, 31b), the device being characterized in that each one of said first or second stroke limiting pivots (25a, 25b, 26a, 26b) is magnetized and constituted by a cylindrical magnet that is arranged axially with respect to a sleeve that protrudes from a footing that is arranged with said profiles (31a, 31b), said sleeve being selectively and slideably arranged inside metallic jackets (24a, 24b) of the rectilinear hollow bodies (8a, 8b) wherein the bidirectional shock absorber is constituted by a pair of hollow deceleration cylinders (20a, 20b) that are connected axially by a pivot which is partially and slideably associated therein,and has, at its centerline, a disk for the interposition of a cylindrical helical compression spring (23a, 23b) between said disk and the facing end of said deceleration cylinders (20a, 20b) and wherein each of the metallic jackets (24a, 24b) is associated coaxially with one of said deceleration cylinders (20a, 20b) and in turn is arranged coaxially to one of the ends of said rectilinear hollow body (8a, 8b). a rectilinear hollow body (8a, 8b) made of plastic material wherein said rectilinear hollow body (8a, 8b) accommodates a bidirectional shock absorber; a profile (31a, 31b) that is mountable with the top of said piece of furniture; wherein said rectilinear hollow body (8a, 8b) is slideably associated with said profile (31a, 31b) and can be coupled automatically and with a snap action to an entrainer (10a, 10b) of said device that is fixable to one of said door leaves (2a, 2b) by way of a carriage (11a, 11b, 14a, 14b) of said device; and a first or a second stroke limiting pivot (25a, 25b, 26a, 26b) wherein said rectilinear hollow body (8a, 8b) interacts selectively with the first or the second stroke limiting pivot (25a, 25b, 26a, 26b) which are associated with said profile (31a, 31b), the device being characterized in that each one of said first or second stroke limiting pivots (25a, 25b, 26a, 26b) is magnetized and constituted by a cylindrical magnet that is arranged axially with respect to a sleeve that protrudes from a footing that is arranged with said profiles (31a, 31b), said sleeve being selectively and slideably arranged inside metallic jackets (24a, 24b) of the rectilinear hollow bodies (8a, 8b) wherein the bidirectional shock absorber is constituted by a pair of hollow deceleration cylinders (20a, 20b) that are connected axially by a pivot which is partially and slideably associated therein,and has, at its centerline, a disk for the interposition of a cylindrical helical compression spring (23a, 23b) between said disk and the facing end of said deceleration cylinders (20a, 20b) and wherein each of the metallic jackets (24a, 24b) is associated coaxially with one of said deceleration cylinders (20a, 20b) and in turn is arranged coaxially to one of the ends of said rectilinear hollow body (8a, 8b).