The effects of ply and single twists on tensile, hairiness and abrasion resistance properties of two-ply yarns with three different yam counts were investigated. Tensile test results showed that the effect of ply twist on breaking strength properties of ply yarns was similar to the effect of the twist on the breaking strength of single yarns. Increases in single twist caused decreases in the strength of ply yarns. Increases in both single and ply twists caused increases in the breaking elongation of ply yarns. Single and ply twists affected the hairiness properties of ply yarns and hairiness values decreased as twist levels increased. Ply twist was more effective on hairiness properties than single twist. Abrasion resistance increased both in fine and coarse yarns as ply twist increased. Any important effect of single twist was not observed on abrasion resistance in fine ply yarn while abrasion resistance increased in coarse yams in the case of low single twist level.