A primary carpet backing is provided for use in the formation of a tufted carpet which eliminates or reduces the need for a latex adhesive layer or the use of a secondary backing. The external surfaces of a woven or non-woven fibrous mat are coated with thermoplastic polymer particles having a lower melting temperature than the fibers of the mat. The mat possesses sufficient openings between fibers to be capable of undergoing tufting. Following tufting the tufted mat is heat treated so as to melt the thermoplastic polymer particles and to create a bond between the tufted carpet yarn fibers and the primary backing mat.