Field cleaning of conventional stripper-type cottons during the brush stripping operation produced cleaner seed cotton and lint than did comparable cotton harvested without the field cleaner. Significant improvements in lint foreign matter levels were noted at each stage of lint cleaning, and these improvements in trash level resulted in somewhat higher color and leaf grades for field cleaned cotton. Field cleaning also tended slightly to increase some fiber maturity measurements and, in a few cases, to lower nep levels in fiber and yarn. Field cleaning did not affect any of the fiber length parameters, and its effects on the quality of ring and open-end yarns were minimal.