© 2020. Carpathian Journal of Food Science and Technology. All Rights Reserved.The current study was aimed at investigating the impact of olive leaf extracts (OLE) on the quality parameters of white and dark muscles from fillets of frigate mackerel (Auxis thazard) stored under vacuum pack (VP) at a refrigerated temperature (3±1°C). The sensory assessment indicated that both muscle types of frigate mackerel had 12 days of shelf-life, while the application of OLE extended the shelf-life by 3 and 6 days in the white and dark muscles, respectively. However, total volatile base-nitrogen exhibited a longer shelf-life in all samples, while thiobarbituric acid values showed shorter shelf-life for control samples. OLE application initiated the lipid peroxidation in white muscle at an early stage of storage and improved the microbiological quality of both muscles by reducing bacterial growth. An assessment of various texture related parameters indicated that VP alone could not enhance the textural quality in both muscles, while OLE improved adhesiveness and circumvented the softening of both frigate mackerel muscles.