The experiment was carried out on 720 Cobb 500 broiler chickens, reared to 42 days. Various forms of vitamin D3 were the group-differentiating factors (cholecalciferol and calcidiol), given in starter, grower and finisher feed mixtures. The control group (group I) received the feed mixture which contained 4000 IU of vitamin D₃ (cholecalciferol), group II received 2500 IU of vitamin D₃ and 1500 IU of calcidiol (25-OH-D₃) and group III – 1240 IU of vitamin D₃ and 2760 IU of calcidiol (25-OH-D3). The aim of the study was to determine the effect of different forms of vitamin D₃ (cholecalciferol and calcidiol) in feed on production yield and meat quality. The results showed the usefulness of partial replacement of vitamin D₃ with calcidiol. With the application of 1500 IU (25-OH-D₃) in the diet of broiler chickens, higher body weight at the end of the rearing period was obtained in comparison to the birds from the control group. The chickens from group III, receiving 2760 IU of calcidiol in their diet, had lower body weight on the 42^nd day in comparison to the chickens from group II; but also a lower mortality and the lowest feed conversion per one kg of body weight gain was observed in that group. The partial replacement of vitamin D₃ with calcidiol in chickens’ nutrition did not have any effect on dressing percentage of males and females; differences were only found in the percentage of offals, especially in the increased heart mass in males from group III. Improvement was observed in the physicochemical properties (higher water absorption and lower drip after thermal treatment) and in the chemical composition of meat in the group of chickens fed the diet with the addition of calcidiol. Leg muscles from the chickens from group II had higher protein content. Fat in leg muscles and abdominal fat of the chickens from the experimental groups (group II and III) included a significantly higher quantity of monounsaturated fatty acids and a lower content of polyunsaturated acids, especially from the n-6 family, as compared to the control group. Moreover, the addition of calcidiol in the mixtures caused a decrease in the rate of oxidation of lipids in abdominal fat of the chickens in comparison to the control group.