Sulfated polysaccharides (SPs) were extracted from red algae, Pterocladia capillacea and the produced fractions were hydrolyzed using different enzymes. 1,1-Diphenyl-2-Picryl-Hydrazyl (DPPH) and peroxide scavenging activities as well as phenolic content of the extracted fractions and their hydrolysates were determined. Viscozyme hydrolysate exhibited the highest phenolic content and a DPPH scavenging activity of about 92% with more than 50% increase over its mother fraction. It also showed a high antibacterial activity relative to commercial antibiotics. Phenolic content determination and HPLC analysis suggested that the high antioxidant activity of viscozyme hydrolysate could be owed to its short-length chain and its high content of phenolic compounds as well as the predominance of mannose and galactose sugars in the polysaccharide chain.