Leaves of fresh coriander (Coriandrum sativum L.) were treated with 5, 10 or 15 ppm solns. of O3 and then subjected to microbiol., sensory (color, taste, texture) and chem. (content of chlorophyll, carotenoids, vitamin C, polyphenols and flavonoids) assessment after 0, 3, 6, and 9 days of storage. Content of the chlorophyll, carotenoids and vitamin C decreased during storage, while content of polyphenols increased noticeably. Antioxidant activity remained unchanged.