In this paper, the dimensional and some physical properties of a series of plain jersey and lacoste fabrics made from both cotton ring and open-end spun yams are investigated. The results show that structural differences in the yam play a large part in determining the dimensions and behavior of these two fabric types. It is apparent that the amount of relaxation shrinkage occurring with open-end spun yam is greater than that with ring spun yam. Furthermore, open-end spun yams tend to be weaker, which results in lower bursting strength, and the fabrics knitted from such yams tend to pill more. Finally, so far as abrasion resistance is concerned, ring spun knits perform slightly better than open-end spun knits.