Fish-by-products; which consists of viscera, head, bones and gills; pose great disposal problem for the fish processing industry. The research was conducted to study the use of enzymatic and microwave hydrolysis to induce the antioxidant activity of fish- viscera hydrolysates. Two kinds of fish, i.e. tuna and sardine, were utilized in the research. Tuna-viscera microwave hydrolysate was proven to exhibit the highest antioxidant activity, followed by tuna-viscera enzymatic hydrolysate, sardine-viscera enzymatic hydrolysate and sardine-viscera microwave hydrolysate. These hydrolysates generally poses higher antioxidant activity compared to a 40 IU vitamin E.