The aim of this study was the comparison of growth parameters, yields and qualitative properties of muscles in broiler hybrids ISA 220 and intermediate type ISA 257. One hundred and one one-day-old chicks, comprising approximately equal numbers of males and females were used. During the experiment the feed consumption (per 1 kg of body weight gain), weight gains, and body weight were recorded. After the processing of the broiler chickens, the weight of carcass, and yields (of the whole carcass, breast muscle, thighs, boned thigh muscles, wings, skeleton) were recorded. The breast and thigh muscles were analyzed for the content of nitrogen compounds, fat, water, amino acid, and weight losses during the cooking. The sensory properties of breast and thigh muscles of both groups were compared. The mean body weight of the broiler chickens at the beginning of the experiment was 43 g (ISA 257), and 36 g (ISA 220) respectively. On day 45, the mean body weights and carcasses were significantly higher (p < 0.05) in group ISA 220 (2507 g and 1676 g respectively) in comparison with ISA 257 (1890 g and 1249 g). These results corresponded with the results of carcass yields. The mean yield of the whole carcass was significantly higher (p < 0.05) in ISA 220 (66.64%) in comparison with ISA 257 (66.06%). However, the mean yields of thighs, boned thigh muscle, and wings, which are considered as ideal parts, for grilling were significantly higher (p < 0.05) in ISA 257. Higher differences were recorded in fat and water content. The hybrids ISA 220 contained a higher amount of water in breast and thigh meat, and fat content was higher in meat of ISA 257, mainly in breast meat. The results of sensory examination showed better acceptability of ISA 257 hybrid than ISA 220.