Fiber cleaning became an essential process in cotton gins with the introduction of mechanical harvesting. From the beginning, researchers working on this topic realized that the cleaning process diminished the performance characteristics of the fiber in later textile processes. Numerous research reports over the past thirty years document the effect of cleaning processes on fiber properties and performance. No data were found that showed a clear-cut advantage to be gained by using a mill-type cleaning strategy. Reports from some very recent research projects were not available for review. The marketing system places a high value on cleanness of fiber. There is no clear indication that future marketing systems will radically change this appraisal. It behooves the production and ginning interests to develop and use cleaning processes that accomplish the desired cleaning effect with minimal fiber damage.