The objective of the present study was to determine the differences in the fatness and musculature between gilts and castrated males placed within the higher classes of the EUROP classification system (E,U,R). The material investigated were 409 carcasses of fatteners from individual farms,; their external conformation was similar to the Polish large white (wbp) and the Polish landrace (pbz) breeds. The thickness of backfat above a gluteus medius muscle (on loin I, II, III) and the thickness of fat on the back of gilts carcasses in the R class were about 1 cm higher if compared with the gilts carcasses of the E class. The gilts had a thinner backfat thickness than the castrated males, regardless of the class under the EUROP classification system. However, carcasses of the investigated castrated males were more fatty and worse muscled if compared with the gilts carcasses in the best rated classes of the EUROP classification system.