The aim of this research was to study the lipid fraction composition of late lactation mares’ milk produced by Polish Cold-blooded mares between 141 and 210 d post partum. Total fat, cholesterol, fatty acids composition, fat soluble vitamins and β-carotene content were measured. The study revealed that mares’ milk is a low fat product with low cholesterol content. The lipid fraction of mares’ milk was characterised by a low concentration of saturated fatty acids, as well as low ratio of linoleic and linolenic fatty acids. The results obtained showed that, despite its low fat content, mares’ milk is a good source of fat-soluble vitamins, especially vitamins D3, E and K2.