Seat-cover or back-cover strip for seats of motor-vehicles, comprising: - a band made of an elastic fabric; - upper anchoring means comprising in turn: i) one or more threads, for fixing the strip to support bars of a headrest of seats of motor-vehicles, each having attaching devices (9a, 9b, 9c), whereby some of them engage hooking apparatuses (28a, 28b, 28c), others directly engage: ii) at least one removable rod, having a polygonal cross-section, cooperating with one or more threads directly or by said hooking apparatuses (28a, 28b, 28c); said upper anchoring means being positioned so that the rod engages loops made in the upper portion of the band, or in an open-work sheath, having holes for receiving the threads in predetermined positions as a function of the type of the used upper anchoring means, and in that the threads engage around said support bars; - lower anchoring means comprising in turn: a) at least one pipe which is inserted in a pocket having at least one small hole through which it projects, b) at least one tape having at least one hook joinable to the free end of a further tape, partially folded on the same forming a stop for a loop-shaped thread of a material analogous to the thread, fixable to the portion under the base of seats. - a band made of an elastic fabric; - upper anchoring means comprising in turn: i) one or more threads, for fixing the strip to support bars of a headrest of seats of motor-vehicles, each having attaching devices (9a, 9b, 9c), whereby some of them engage hooking apparatuses (28a, 28b, 28c), others directly engage: ii) at least one removable rod, having a polygonal cross-section, cooperating with one or more threads directly or by said hooking apparatuses (28a, 28b, 28c); said upper anchoring means being positioned so that the rod engages loops made in the upper portion of the band, or in an open-work sheath, having holes for receiving the threads in predetermined positions as a function of the type of the used upper anchoring means, and in that the threads engage around said support bars; i) one or more threads, for fixing the strip to support bars of a headrest of seats of motor-vehicles, each having attaching devices (9a, 9b, 9c), whereby some of them engage hooking apparatuses (28a, 28b, 28c), others directly engage: ii) at least one removable rod, having a polygonal cross-section, cooperating with one or more threads directly or by said hooking apparatuses (28a, 28b, 28c); said upper anchoring means being positioned so that the rod engages loops made in the upper portion of the band, or in an open-work sheath, having holes for receiving the threads in predetermined positions as a function of the type of the used upper anchoring means, and in that the threads engage around said support bars; - lower anchoring means comprising in turn: a) at least one pipe which is inserted in a pocket having at least one small hole through which it projects, b) at least one tape having at least one hook joinable to the free end of a further tape, partially folded on the same forming a stop for a loop-shaped thread of a material analogous to the thread, fixable to the portion under the base of seats. a) at least one pipe which is inserted in a pocket having at least one small hole through which it projects, b) at least one tape having at least one hook joinable to the free end of a further tape, partially folded on the same forming a stop for a loop-shaped thread of a material analogous to the thread, fixable to the portion under the base of seats.