Effect of twist multipliers on single jersey and rib1x1 knitted fabrics was studied. For this study three different twist multipliers of 40Ne (English count) ring spun yarns were used. The yarns were produced from 100% cotton imported from India and its properties are identified and used for the manufacturing of yarn with three different twist multipliers. In this study the fiber, yarn, spinning, and knitting parameters and properties are kept constant whereas twist multiplier of yarn varied. Both single jersey and rib1x1 knitted fabrics produced from the three different twist multipliers (TM) such as 3.6, 4.2 and 4.8 with the twist levels of 900, 1050 and 1200 turns/m twist of yarns. Effect of twist multipliers on the dimensional, mechanical and comfort properties of single jersey and rib1x1 knitted fabrics were studied. The result and analysis showed that the effect is significant on loop length, fabric weight, thickness, tightness factor, stitch density, loop shape factor, bursting strength, abrasion resistance, pilling resistance and air permeability properties but with different value on the single jersey and rib 1x1 knitted fabrics. Key words: - Twist multipliers, single jersey and rib1x1 knitted fabrics, effects, knitted fabric properties