How Long Does Diced Tomatoes (Canned) Last?

Opened canned diced tomatoes last 5-7 days in the fridge, the same window as tomato sauce and paste, since all three share the same basic cooked, acidic tomato composition that offers modest natural resistance to bacterial growth compared to a neutral-pH liquid.

A sour, fermented smell beyond the can's normal tangy aroma, visible mold on the surface, or a notably slimy texture to the tomato pieces themselves are the clear signs a container should be discarded — the liquid can look slightly cloudier than fresh from the can even when still fine, so smell is the more trustworthy check than appearance alone.

Moving opened canned tomatoes into a non-metal container before refrigerating is commonly recommended, since the tomatoes' acidity can interact with a can's lining over several days sitting in the fridge — worth doing as routine caution even though modern can linings are designed to resist this interaction better than older cans were. A can that's been opened but only partially used is sometimes left covered loosely with plastic wrap directly over the can's open top rather than transferred to a separate container — a shortcut that works for a day or so but isn't ideal for the full 5-7 day window, since a proper airtight seal protects flavor and limits air exposure better than wrap alone. A can of petite diced tomatoes, cut into smaller pieces than the standard diced style, follows the identical 5-7 day opened window and spoilage signs as regular diced tomatoes — the smaller cut size is purely a texture choice for a specific recipe and doesn't change how quickly the can spoils once opened.

See Diced Tomatoes (Canned)'s full storage & shelf-life guide (with spoilage signs) →