A tire is a composite of rubber and reinforcing materials. Polymeric materials used as reinforcing components are usually synthetic yarns. These synthetic yarns have high tenacity, they are made of continuous multifilaments. The yarns are converted in the cord form to provide desired mechanical, thermal and adhesion properties by a series of conversion processes. Besides of multifilament synthetic cords, there are some specific areas in which single ply monofilament cords have been utilized as a reinforcing element. In this study, new cord structures have been developed by using monofilament yarns and by imitating multifilament cords. New cord structures exhibited some very interesting cord properties compared to both single ply monofilament cord and multifilament cords. Monofilament yarns having diameter between 0.23 and 0.50 mm have been twisted together from 3 to 6 plies based on mixed Taguchi model to form cords. Nylon 6.6 and Polyester monofilament yarns have been selected because of common application of their multifilament counterpart yarns in tire carcass and capply. The twisted monofilament cords have been adhesive treated to produce cords ready to adhere rubber. The mechanical properties, thermal stability, adhesion with rubber, fatigue properties under dynamic conditions, retention of properties after curing and microscopic analysis of the cords have been analyzed. The cords have been found to possess some benefits for tire carcass, breaker, belt and belt protective layer applications with their superior fatigue performance, cut resistance, stiffness, ligth weigth etc.