Technical Abstract: A two year, belt-wide commercial cotton gin sampling project was conducted during the 2005-06 and 2006-07 ginning seasons to assess the changes in upland cotton quality during the ginning process and throughout the ginning season across the entire cotton belt. This report summarizes the cotton quality information collected to establish a baseline for future research efforts to address cotton short fiber content and fiber entanglements, called neps, that occur during processing. Fiber quality measurements of ginned lint sampled before and after lint cleaning followed expected trends in that lint cleaning improved color grades, reduced foreign matter content and fiber length and length uniformity, and increased short fiber content and neps. Fiber quality measurements before and after lint cleaning summarized by cotton growing region showed similar trends to those summarized across the cotton belt. Differences in fiber quality measurements among regions were presented but not compared as many could likely be attributed to varietal and environmental differences among sampling sites. As part of a broader effort, this report should aid in developing innovative approaches to clean and maintain the quality of cotton fiber, while reducing short fiber content and neps.