The present study studied the effects of fish gelatin (FG) incorporated with grape seed extract (GSE) through vacuum impregnation (VI) on refrigerated tilapia ( Oreochromis niloticus ) fillets over 12 days. The VI of FG-GSE significantly improved the quality of the fish by decreasing drip loss , texture changes, and microbial survival. It also delayed protein oxidation by inhibiting the formation of disulphide bonds and carbonyl groups, and maintaining a higher sulfhydryl content and Ca 2+ -ATPase activity. Regarding myofibril degradation, FG-GSE maintained their secondary structure by increasing the ratio of α-helices and β-sheets (70.88–75.51%). Atomic force microscopy further revealed that the FG-GSE coating preserved the myofibril nanostructure by maintaining their length, width, and height. Overall, the synergistic effects of VI with 3% FG and 0.9% GSE suggested a promising approach for fillet preservation.