Food would appear to be one of the main ways of animal and human contamination with polycyclic aromatic hydrocarbons (PAHs). Many studies have shown the presence of PAHs in milk and dairy products, suggesting that they can represent a part of this contamination. Our work aimed at defining in vitro the mammary barrier role in PAH transfer to milk. Mac T cells were cultivated on permeable filters to measure transepithelial permeability of 14C labelled benzo[a]pyrene, pyrene and phenanthrene which differed in their physicochemical properties. The results showed that only two molecules, phenanthrene and pyrene, were able to cross mammary cell layers. Phenanthrene radioactivity appeared more quickly in apical media and its level after a six-hour exposure was 1.3 times higher than for pyrene and 7.7 times higher than for benzo[a]pyrene. These findings suggested that mammary epithelium could play a key role in the selective transfer of PAHs from food to milk.