Fernandes, J. I. M., Murakami, A. E., Gomes de Souza, L. M., Ospina-Rojas, I. C. and Rossi, R. M. 2014. Effect of arginine supplementation of broiler breeder hens on progeny performance. Can. J. Anim. Sci. 94: 313-321. Two experiments were conducted to determine the effects of arginine (Arg) supplementation of broiler breeder hens on the performance, carcass yield, and bone measurements of their progeny. In both experiments, the maternal diet was supplemented with five levels of digestible Arg (0.94, 1.09, 1.24, 1.39 and 1.54%). In exp. 1, a total progeny of 1050 chicks were housed in pens according to maternal diet and fed a typical diet without L-Arg supplementation. In exp. 2, a total progeny of 960 chicks were kept in pens according to maternal diet and fed diets containing supplemental L-Arg from 1.30 to 1.90% in the starter phase and from 1.15 to 1.75% in the grower phase. The data obtained in both experiments were deployed in orthogonal polynomials to allow for an analysis of variance and a regression analysis. In the starter phase, there was a quadratic effect (P<0.05) of Arg level in the maternal diet on the feed:gain ratio of the non-supplemented progeny. In the Arg-supplemented progeny, there was a quadratic effect (P<0.05) of Arg level on the feed intake and feed:gain ratio and a linear increase (P<0.05) in body weight gain, and carcass and breast yields (P<0.05). Femur length, tibia diameter, and the Seedor index of both bones increased linearly (P<0.05) in broilers fed the Arg-supplemented diet. Arg supplementation in the broiler breeder hen diets had little positive effect on the non-supplemented progeny; thus, Arg supplementation in the progeny diet is necessary to optimize performance, carcass yield, and bone quality of these hens′progeny.