A safety device (1, 1') for struts adapted to be used with struts of the type comprising an outer tube with an upper threaded portion comprising two longitudinal and diametrically opposed slots, an inner tube telescopically housed in the outer tube comprising at least two diametrically opposed holes, a nut that can be threaded to the upper threaded portion of the outer tube, and a pin that can be housed both in the two slots of the outer tube and in the two holes of the inner tube, the safety device (1, 1') for struts comprising a base (2, 2'), which: - has at least one U-shaped portion, defined by a central section, and extremities, with the separation between at least one portion of the extremities (22, 22') thereof being longer than the width of the outer tube, while being shorter than the length of the pin and the width of the nut, and - is adapted in a lock condition of the safety device (1, 1') for struts, to be positioned with said portion of the extremities (22, 22') thereof around the upper threaded portion of the outer tube, while being supported by the nut and with the central section of the base (2, 2') being separated from the outer tube, the safety device (1, 1') for struts having - the upper surface of each extremity (22, 22') of the base (2, 2') comprising an inclined portion, both inclined portions of said extremities (22,22') being symmetrical to each other relative to the vertical plane of symmetry of the base (2, 2') and the lower ends thereof being situated on the side of the central section of the base (2, 2'), and being characterised in that the safety device comprises a latch with at least one U-shaped portion affixed in an articulated manner by its central section to the central section of the base (2, 2'), which can freely rotate relative to an axis perpendicular to the vertical plane of symmetry of the base (2, 2'), having at least one protrusion comprised in at least one of the extremities, the size thereof being such that, in its lock condition, the extremities thereof can rest on said inclined portions. - has at least one U-shaped portion, defined by a central section, and extremities, with the separation between at least one portion of the extremities (22, 22') thereof being longer than the width of the outer tube, while being shorter than the length of the pin and the width of the nut, and - is adapted in a lock condition of the safety device (1, 1') for struts, to be positioned with said portion of the extremities (22, 22') thereof around the upper threaded portion of the outer tube, while being supported by the nut and with the central section of the base (2, 2') being separated from the outer tube, the safety device (1, 1') for struts having - the upper surface of each extremity (22, 22') of the base (2, 2') comprising an inclined portion, both inclined portions of said extremities (22,22') being symmetrical to each other relative to the vertical plane of symmetry of the base (2, 2') and the lower ends thereof being situated on the side of the central section of the base (2, 2'), and being characterised in that the safety device comprises a latch with at least one U-shaped portion affixed in an articulated manner by its central section to the central section of the base (2, 2'), which can freely rotate relative to an axis perpendicular to the vertical plane of symmetry of the base (2, 2'), having at least one protrusion comprised in at least one of the extremities, the size thereof being such that, in its lock condition, the extremities thereof can rest on said inclined portions.