The ginning characteristics of 30 cotton varieties were determined by processing samples grown in 6 replications in two fields near Stoneville, MS. Most of the fiber quality and yield parameters were different for varieties. Foreign matter was removed with different degrees of efficiency for the varieties. When the initial seed cotton foreign matter was adjusted to a common level, the cleanability ranged from 51% for HS-23 to 72% for Deltapine 51. When the foreign matter before lint cleaning was adjusted to a common level, the lint cleaning efficiency ranged from 48.4% for Stoneville 453 to 66.3% for Deltapine 50. Lint turnout (adjusted to a common level of initial foreign matter and moisture) after gin processing was about 3.7% lower than the lint percent and the differences ranged from 1.3% to 5.9%. This variation indicates that the varieties do not respond identically to ginning, and should be evaluated after standard gin processing in addition to currently used methods. Lint yield per acre ranged from a low of 809 pounds for Deltapine 5690 on sandy soil to a high of 1312 pounds for HX-1215 on mixed soil. Lint grade indices ranged from 92.6 for HS-23 to 99.4 for Deltapine 51. Monetary values per acre ranged from $415.90 for HS-46 on sandy soil to $718.08 for Hartz HX-1215 on mixed soil. Factors other than fiber quality must also be considered in varietal evaluations on an area basis. Factors such as soil type, disease and insect resistance, maturity, and drought tolerance may be more important than grade in some areas.