Fabric having elastane fiber is accepted as fashionable and functional for a long time, especially for the fabrics fit the body in a comfortable way. This study examines the deformation properties of knitted sportswear fabric. Three different test methods were used to compare the stretching abilities of the test fabrics. 12 knitted fabrics were produced according to the customer demands by using two different base yarn linear density (Ne28 viscose, Ne36 viscose), two different settings (normal, tight) and three different poliamid/elastane gimped yarn denier (70/20, 70/40, 70/70)". As a result, comparative analysis has been carried out between these three methods and the effect of structural parameters such as linear density of gimped elastane yarn and fabric setting was analyzed. It was observed that fabrics having Ne28 viscose yarn have generally less deformation values in comparison to the fabrics having Ne36 viscose yarn for the results of different test methods. The effects of structural parameters such as linear density of gimped yarn and setting were found statistically significant at 95% confidence level for many of the test fabrics. Besides, it was found out that there is no systematic tendency observed among the fabric types for the different test methods.