A safety belt, particularly for racing vehicles, comprising: a plurality of tongues each attachable to a respective belt strap, each tongue having at least one through hole for the passage of a respective retaining pin and at least one through opening for the passage of a belt strap; a buckle for mutually locking and releasing the tongues, the buckle comprising: a casing having a plurality of slots each adapted to receive one of the said tongues, a locking and release mechanism for releasably retaining the tongues, the mechanism comprising a plurality of releasable retaining pins adapted to releasably secure a respective plurality of said tongues and a control member, adapted to cause release of the releasable retaining pins, at least one fixed retaining element (13a, 7) for retaining at least one of the tongues, said fixed retaining element (13a, 7) not being releasable by the control member; a fixed tongue for a fixed strap of the safety belt, the fixed tongue being made by a single piece of a shaped plate which forms at least one through opening for the passage of at least one strap of the belt and at least one through hole (21a, 22) for the passage of the fixed retaining element (13a, 7); the fixed tongue further forming a plurality of through holes for the passage of a respective plurality of releasable retaining pins of the buckle; characterized in that the fixed tongue forms at least two of said through openings, which are adjacent or consecutive in a circumferential direction with respect to a substantially central axis which is perpendicular to a geometrical plane wherein the fixed tongue lies; that the through openings are elongated in tangential directions with respect to the axis, and that the fixed tongue forms a substantially central opening. a plurality of tongues each attachable to a respective belt strap, each tongue having at least one through hole for the passage of a respective retaining pin and at least one through opening for the passage of a belt strap; a buckle for mutually locking and releasing the tongues, the buckle comprising: a casing having a plurality of slots each adapted to receive one of the said tongues, a locking and release mechanism for releasably retaining the tongues, the mechanism comprising a plurality of releasable retaining pins adapted to releasably secure a respective plurality of said tongues and a control member, adapted to cause release of the releasable retaining pins, at least one fixed retaining element (13a, 7) for retaining at least one of the tongues, said fixed retaining element (13a, 7) not being releasable by the control member; a fixed tongue for a fixed strap of the safety belt, the fixed tongue being made by a single piece of a shaped plate which forms at least one through opening for the passage of at least one strap of the belt and at least one through hole (21a, 22) for the passage of the fixed retaining element (13a, 7); the fixed tongue further forming a plurality of through holes for the a casing having a plurality of slots each adapted to receive one of the said tongues, a locking and release mechanism for releasably retaining the tongues, the mechanism comprising a plurality of releasable retaining pins adapted to releasably secure a respective plurality of said tongues and a control member, adapted to cause release of the releasable retaining pins, at least one fixed retaining element (13a, 7) for retaining at least one of the tongues, said fixed retaining element (13a, 7) not being releasable by the control member; a fixed tongue for a fixed strap of the safety belt, the fixed tongue being made by a single piece of a shaped plate which forms at least one through opening for the passage of at least one strap of the belt and at least one through hole (21a, 22) for the passage of the fixed retaining element (13a, 7); the fixed tongue further forming a plurality of through holes for the passage of a respective plurality of releasable retaining pins of the buckle; characterized in that the fixed tongue forms at least two of said through openings, which are adjacent or consecutive in a circumferential direction with respect to a substantially central axis which is perpendicular to a geometrical plane wherein the fixed tongue lies; that the through openings are elongated in tangential directions with respect to the axis, and that the fixed tongue forms a substantially central opening.