Upland cotton gins across the cotton belt were sampled during the 2005-06 ginning season to assess the changes in upland cotton quality during the ginning process and throughout the ginning season. Three to five gins were targeted per region: Far-west, Southwest, Mid-south, and Southeast and gin size averaged at least 30,000 bales. Samples were taken at the module, feeder apron, before each lint cleaner, and after lint cleaning at regular intervals in the season. Seed cotton samples were ginned on a small breeder gin and by hand to obtain lint samples. High Volume Instrument (HVI), Advance Fiber Information System (AFIS), and Micro Dust and Trash Analyzer III analyses were performed on the lint samples obtained from the commercial gins and lint samples from the breeder and hand ginned seed cotton samples. Results were analyzed to evaluate changes in fiber quality, especially trash content, short fiber content and neps, at each step in the ginning process and as the ginning season progressed.