Technical Abstract: A study was carried to obtain a quantitative assessment of how the presence of short fiber (< 12.5 mm long) in raw cotton affect the quality of ring yarn spun from the mix. Properties of the raw cotton were measured on HVI and AFIS instruments and by the manual Suter-Webb Array method. Twenty-nine bales of cotton were acquired with a wide range of fiber properties having an especially diverse population of short fiber contents. Ring yarns produced from the subject cottons were tested for process and product quality. Results indicated that most of the yarn properties correlated with all of the measures of short fiber content. This was especially true for yarn strength, irregularity, and the frequency of thick and thin defects. A pool of 23 potential predictors from the AFIS, HVI and Suter-Webb fiber properties was utilized to develop `best¿ models for seven yarn properties. In five of the seven models, the short fiber content variable was the most important predictor, exceptions being the models for yarn strength and elongation. For five of the yarn properties, models built from the basic HVI properties alone were nearly as good as those build from all of the 23 fiber properties. Exceptions were models for elongation and for ends down.