The present work investigated the antimicrobial and antioxidant activities of polyphenols extracted from cactus (Opuntia ficus indica) fruit-peels on sardine fillets during refrigerated storage. Biochemical, microbiological and sensorial indicators of treated sardine fillets; were studied comparatively to control lot. Microbial communities were characterized using phenotyping and molecular identification of bacterial isolates; and culture-independent method (PCR-TTGE) for fingerprinting of bacterial DNA extracted from fillets. A principal component analysis (PCA) of all the studied descriptors and variables revealed that discrimination along first principal component (PC1) was mainly correlated positively with peroxidation level and storage time but negatively with polyphenol treatment while along second component (PC2) it was mainly positively correlated to polyphenols treatment and polyene index; confirming the effect of treatment on preservation of sardine fillets. Sensory data studied by the correspondence factorial analysis (CFA) revealed that the addition polyphenols extract extended the shelf life of sardines without altering their sensorial properties. Cactus fruit-peels appeared a promising source of natural bio-preservative agent for aquatic food processing.