During the harmonization of Slovene legislation with legislation of European Union new categories of milk were set. Therefore the percentage of milk fat in some types of liquid milk products had to be changed. The intention of our research was to find out whether consumers know the content of milk fat in products they buy. The question whether consumers were aware of the change in milk fat content introduced by new legislation was also investigated. It was found out that more than 70% of consumers precisely identify the number written on packaging which is associated with fat content, but no one knows the real meaning of this number. Almost half of consumers who bought milk with 3,5% of milk fat thought that they bought milk with 3,2% milk fat.