The limited knowledge of horse´s olfaction poses a risk that horse behaviour does not match human expectation. Therefore, investigation of olfactory abilities can lead to better understanding of horses´ behaviour. Horses were able to detect and distinguish between 4 odours: peppermint, orange, lavender and cedar wood, and sniffed peppermint longer than all other odours. Horses´ sniffing duration varied with age and pregnancy status, younger horses sniffed cedar wood longer, and pregnant mares sniffed lavender less.