The aim of the research was to investigate the changes of the milkfat with sunflower oil mixtures as a result of the interesterification in the presence of enzymatic preparation Novozym 435. The subject of the examination were the milkfat with sunflower oil mixtures with the following weight composition: 1:3, 1:1, 3:1. The mixtures have been interesterified at the temperature of 80°C for 2, 4 and 8 hours in the presence of enzymatic preparation Novozym 435. After interesterification an increase in the free fatty acids content for all mixtures was observed. The slip melting temperatures and the solid fat contents of the interesterification products depended on the mixtures composition before the process. The interesterification has not influenced the composition of the fatty acids in triacylglycerols, but the structure of the triacylglycerols changed.