Tips. 1  How long does tuna salad last in the fridge? The precise answer to that question depends to a large extent on storage conditions - refrigerate tuna salad within two hours of preparing or purchasing. 2  To maximize the shelf life of tuna salad for safety and quality, refrigerate the tuna salad in airtight containers. Properly stored, tuna salad will last for 3 to 5 days in the refrigerator. How long can tuna salad be left at room temperature? Bacteria grow rapidly at temperatures between 40 °F and 140 °F; tuna salad should be discarded if left out for more than 2 hours at room temperature.