The use of new technologies / processes provides different benefits on seafood sector, namely by enhanced the shelf-life of fish products with high polyunsaturated fatty acid composition. This is particularly critical during some months of the year when fish (e.g. sardines) are larger supply than demand by consumers. The aim of this study was to performed the optimization process of adding natural antioxidants on frozen sardine fillets and evaluated the effect of addition of two natural antioxidants on the lipid oxidation process during storage at -200C. To evaluate the effect of the addition of antioxidants in sardine fillets, the product matrix was chemical characterized, including by the evaluation of the fatty acid profile. The lipid oxidation process was followed by the primary products (peroxide value) and secondary products (TBARS) quantification, and also by the analysis of the sensory changes (instrumental assessment of color). Finally, it was done a hedonic preference test to know the opinion of consumers about the frozen fillets with and without antioxidant. The natural antioxidants used, tocopherol (54 mg/fillet) and tocopherols (15 mg/fillet) with rosemary extract (6.5 mg/fillet) inhibited or retarded the oxidation over time of storage when compared with the control samples, that had advanced oxidation process. There was not statistically differences among the fillets treated with tocopherol in the presence and absence of rosemary extract. However, our laboratorial results shown slight tendency for the view that the antioxidant tocopherols and rosemary extract had a greater effect on the oxidative stability of fillets. This observation is in line with results of the hedonic test consumer preference. The use of natural antioxidants is an inexpensive solution which allows the complete use of products with less waste of fish products and with a great need for disposal. At the same time meets the consumer´s requirements.