The research concerned the sexual dimorphism in body weight of BUT9 and BIG6 turkey chicks. The first group included 4000 females and 4000 males of BUT9 turkeys and 1500 males and 1500 females of BIG6 poults. The second comprised two combinations of 5000 BUT9 turkeys in each group of both sexes. All birds were weighed on the farm and bred as young turkey broilers. Average body mass of males was 61.35g and 56.47g, adequately, at first and second groups of BUT9 birds. For females it amounted to 58.00g and 55.34g. Males of BIG6 turkeys weighed 57.80g and females 56.00g. Ascertained differences were statistically significant independently of the groups in middle-heavy and heavy turkeys. Similar relationships were also noticed in 7-dayold turkey chicks.