This survey concerned frozen celeriac produced using a traditional method, i.e. from the raw material blanched before freezing, and a modified method of freezing cooked vegetable. The content of selected constituents having antioxidative properties, and sensorial quality were evaluated. In comparison with blanched celeriac, the material cooked before freezing contained more dry matter, polyphenols and beta-carotene, and less vitamin C and carotenoids; its antioxidative activity was also poorer. In frozen products stored for 0, 4, 8 and 12 months at -20°C or -30°C and then prepared for consumption, a steady decrease was observed in the content of analysed constituents. A higher or similar level of the above properties was found in frozen products cooked before freezing as compared with blanched ones; a higher level was ascertained in samples stored at -30°C compared with those stored at -20°C. prepared for consumption from cooked product were evaluated lower than obtained from blanched celeriac. Frozen products stored for 12 months at -30°C had a higher sensory quality than those stored at -20°C.