Fatness traits, including fatty acid (FA) composition, influence the dietary value of meat products. In this study we compared the fatty acid profiles in the carcasses of two main Polish breeds, Polish Large White (PLW) and Polish Landrace (PL), and two common commercial ones, Duroc and Pietrain. The Longissimus dorsi muscle, subcutaneous and visceral fats were sampled from 85 gilts that were fed the same diets and slaughtered at the same body weight (100 kg). Several significant between-breed differences were observed in FA composition, especially in subcutaneous and abdominal fat. In all tissues, the lowest percentage of saturated fatty acids (SFA) was observed in Pietrain pigs, with the differences depending mainly on C16:0 and C18:0. In abdominal fat, the highest content of monounsaturated fatty acids was found in that of PLW, chiefly due to an elevated content of C18:1 n-9. In both adipose tissues the highest content of polyunsaturated fatty acids (PUFA) was found in Pietrain and the lowest in PLW. These differences were mainly because of the high content of C18:2 in Pietrain pigs. The existence of between-breed and tissue differences was confirmed by linear discriminant analysis, which revealed that the studied tissues can be distinguished according to FA profile with an overall prediction ability of 89.8%. It was also shown that the percentage of PUFA in the studied tissues was negatively correlated with abdominal fat weight. We conclude that the FA profile in the carcass of Pietrain pigs is the most favourable, while two Polish breeds and the Duroc breed have similar FA profiles.