The by-products of the skate processing industry have bioactive properties but are mostly discarded. In the present study, the properties of skate cartilage, a major by-product of skate processing that is rich in chondroitin sulfate (CS) and type II collagen were investigated. Enzymatically-hydrolyzed type II collagen peptides (CP) and thermally hydrolyzed CS oligosaccharides (CSo) from skate cartilage were prepared and their antioxidant activities were studied. High free radical scavenging activity was observed in the