The objective of the study was to prove the possibilities of determining the quality and usefulness of fats in the baking process depending on the composition of fatty acids contained in them. The scope of the study involved the evaluation of the composition of fatty acids contained in six vegetable shortenings, as well as in butter and lard. Additionally, the induction time of each fat was determined using a Rancimat apparatus at a temperature of 150 ºC. The fats investigated significantly differed in the composition of their fatty acids. They were characterized by the following amounts of their fatty acids: SFA: from 20.6 to 69.7 %; trans fat acids (TFA): from 0.2 to 55.9 %; MUFA cis from 22.4 to 46.0; and EFA: from 1.0 to 10.0 %. The induction time ranged from 1.23 to 3.26 h . It has been found that it is possible, using the composition of fatty acids determined by a GC method, to determine the quality and usefulness of fats, and to define thermal treatment conditions. Fats containing a high total amount of SFA and TFA were characterized by a longer induction time. However, a higher amount of NNKT in fats caused the oxidative stability to lower.