This study determined the influence of storage conditions (3 and 6 months at temperatures of 4^oC and 23^oC) on the changes in the fat fraction of UHT milk with 3.2% fat content produced under industrial conditions by two methods of sterilization (indirect and direct). Lipolytic activity, the total content of free fatty acids (FFA), the contents of volatile and non-volatile free fatty acids, the content of peroxides, and acid value were determined as well as a TBA test was conducted. An increase of lipolytic activity in the milk, dependent on temperature and time of storage, was found to occur during UHT milk storage and in consequence a growth of the FFA content in the product was observed. A greater dynamics of FFA content changes was also noticed in milk samples stored at 23^oC rather than 4^oC. In addition, oxidizing changes in UHT milk fat were found and their intensity was higher in the milk stored at room temperature as compared to the milk kept in cold storage.