A vertically integrated monitoring program was set up for breeders hatched in 2013 and their offspring to detect differences in performance related to the reovirus vaccination schedule. Within the same organization in Belgium, 17 breeder flocks were vaccinated with one dose of live and one dose of inactivated reovirus vaccine, while 14 flocks received two doses of inactivated vaccine without live priming. The hatchability of the eggs produced by these birds was examined. Further, the daily growth, feed conversion, mortality, slaughterhouse condemnation, production index, and antibiotic use were monitored in 110 broiler flocks derived from the breeders. All gathered data were examined statistically. In eggs obtained from breeders vaccinated twice with inactivated reovirus vaccine, a significant 2.88% higher hatchability rate was observed. The progeny broiler flocks of these breeders showed a significant 18.2% lower mortality during the fattening period. Although not statistically significant, the slaughterhouse condemnation rate was 10.1% lower as well. The results may indicate that—under the epidemiologic conditions of this study—double administration of inactivated reovirus vaccine in broiler breeders can at least contribute to higher hatchability of breeder eggs and lower broiler mortality.