The aim of the experiment was to compare the effect of different dietary fat sources on performance, biochemical indices and fatty acid profile in the blood serum of broilers. The study was carried out on 96 male Ross 308 chickens from 1 to 42 day of life, fed diets supplemented with soyabean oil (SO), Nowitol 30 (N) and lard (L). The ratio of UFA/SFA in fat sources was: 4.55 (SO), 4.27 (N), 1.75 (L). There was no effect of dietary fat on performance indices, protein and fat metabolism parameters, Ca, P, chloride concentration in the blood. The highest (P<0.05) Mg concentration was found in N group. A higher percentage (P<0.05) of SFA (34.16%) and lower (P<0.05) level of PUFA (54.01%) was found in chickens from group L in comparison with broilers from the SO (SFA - 33.18%, PUFA - 55.84%) and N (SFA - 33.30%, PUFA - 55.99%) groups. The results indicate that performance and biochemical indices were not negatively affected by tested fat sources.