Two spindle harvested Mississippi cottons were processed at two seed cotton cleaning and two lint cleaning levels in the gin. Mill processing and yarn quality were affected to a greater degree by inherent differences in the two cottons than by cleaning levels at the gin. Cottons that received maximum gin cleaning contained less waste and produced higher grades than those cottons that received less than maximum cleaning. Mill processing waste and card room dust levels were lowest for those cottons that received maximum gin cleaning. There were some significant differences in measures of evaluation among spinning performance and yarn quality results due to gin cleaning level, however, these differences did not indicate one particular gin cleaning level as being superior or inferior to the others. These results indicate to the ginner and yarn manufacturer the effects of gin cleaning levels on mill processing performance and yarn quality.