Data from 456 halothane normal purebred Yorkshire, Duroc, and Other breeds pigs from two national progeny testing and genetic evaluation programs were utilized to estimate genetic parameters for carcass components in pigs. Carcass components were cut and weighed according to Institutional Meat Purchase Specifications. Primal cut weights evaluated included 401 Ham (HAM), 410 Loin (LOIN), 405 Picnic shoulder (PIC), 406 Boston Butt (BB), and 409 Belly (BELLY). Individual muscle weights included the inside (INS), outside (OUT) and knuckle (KNU) muscles of the ham, the longissimus dorsi (LD) and psoas major (TEND) of the loin, and the boneless components of both the Boston Butt (BBUTT) and picnic (BPIC). Muscle weights from each primal were summed to yield a boneless sub-primal weight (BHAM, BLOIN, BSHLDR), and all boneless sub-primals were summed to yield total primal boneless lean (LEAN). Heritability estimates for HAM, LOIN, and BELLY were 0.60,0.61, and 0.67, respectively. Heritability estimates for BB and PIC were 0.10 and 0.18, respectively. Heritability estimates for the boneless components of each primal were higher than those for the intact primals. Genetic correlations for HAM, LOIN, and PIC with LMA were 0.57, 0.79, and 0.83, respectively, and -0.66 with BF10. Boneless sub-primal components were highly correlated with LEAN. Gilts had heavier weights (P < 0.01) for all primal cuts (with the exception of BELLY) and boneless sub-primals, individual muscles, and LEAN. Gilts also had less BF10 and more LMA (P < 0.01). Duroc pigs had a heavier (P < 0.01) weight for HAM when compared to Yorkshires, but were not different (P > 0.05) from the Other breed. Yorkshire pigs had more (P < 0.01) LOIN weight than did the Duroc or the Other breed. No breed differences (P > 0.05) were found for BLOIN, BSHLDR, LEAN, or BPIC. Results suggest primal and boneless sub-primal and individual muscle weights in pigs should respond favorably to selection.