Abstract: The effect of rosemary extract on the shelf stability and organoleptic quality of fish stored at 2°C was determined after 0, 3, 6, 9,12 and 15 days of refrigerated storage. Fish fillet (Seriola Dumeriri (treated with 1% (aqueous solution) of rosemary extract had significantly (P<0.05) lower thiobarbituric acid (TBA) and Total Volatile Nitrogen (TV-N) values until 12 day of refrigerated storage compared to control. The result revealed that samples treated with rosemary had lower total bacterial count and psychrophilic count than those of untreated samples. The organoleptic results showed that fish fillets treated with rosemary had a good acceptance throughout storage and rosemary treatment extended the stability of fish fillets to 12 days during refrigerated storage in comparison with the untreated samples.