White meat is the most economically valuable part of a broiler chicken.Increasing white meat relative to overall body size (white meat percentage, WM%)makes a broiler, gram for gram, a more valuable animal. However, accuratelymeasuring WM% requires removing the bird from the breeding flock. Identificationof markers for genomic regions associated with WM% would allow direct geneticselection on breeders. The objective of the current study was to identifygenomic regions affecting WM% and other growth and carcass traits in an F2 crossbetween 2 commercial broiler lines that differed in WM%. Two commercial lineswere crossed to generate 5 F1 half-sib families of each reciprocal cross type.One male from each family was crossed with 3 females from each of the otherfamilies within each reciprocal cross type. Seven F2 half-sib families, totaling430 F2 individuals, were analyzed. Microsatellite markers (n = 73) on the 11largest chromosomes were analyzed for associations with various growth andcarcass traits by least squares interval mapping using line-cross, half-sib,combined, and parent of origin models. Sixty-eight QTL were identified at the 5%chromosome-wise level, including 6 QTL affecting WM%. Ten QTL reached 5%genome-wise significance, including 1 WM% QTL on Gga 2. The current studyidentified genomic regions harboring QTL affecting WM% and other carcass andgrowth traits, which may be useful for direct genetic selection, and alsoidentified putative imprinted QTL in the chicken. The advantage of usingmultiple statistical models was evident because QTL were identified with thecombined and parent of origin models that were not identified with theline-cross or half-sib models.