No, 6-day-old pizza is not safe to eat. The official food safety guideline from FoodSafety.gov is that cooked pizza lasts 3 to 4 days in the refrigerator. At 6 days, your pizza is nearly double the recommended storage window, and harmful bacteria may have grown to levels that can make you sick, even if the pizza looks and smells fine.
Why 3 to 4 Days Is the Limit
Bacteria grow on cooked food even inside a properly functioning refrigerator. Cold temperatures slow that growth dramatically, but they don’t stop it. Between 40°F and 140°F, bacteria can double in number in as little as 20 minutes. Your fridge keeps food below that danger zone, but some bacteria still multiply slowly at refrigerator temperatures. By day 3 or 4, populations of harmful microorganisms can reach levels capable of causing foodborne illness. By day 6, the risk is significantly higher.
Pizza is an especially hospitable environment for bacteria because it combines moisture, protein (cheese, meat toppings), and carbohydrates (dough). These ingredients give bacteria plenty of nutrients to feed on over time.
It Can Look Fine and Still Be Unsafe
The most dangerous thing about old pizza is that it often passes the eye test. You cannot see, smell, or taste the pathogenic microorganisms that cause food poisoning. The bacteria responsible for most foodborne illness are invisible and odorless at the levels needed to make you sick.
Visible spoilage signs do exist: sliminess on the cheese, unnatural discoloration, foul odors, or fuzzy mold growth in white, blue, black, or green patches. But these are caused by spoilage organisms, which are a different group from the pathogens that actually make you ill. If your 6-day-old pizza shows any of these signs, it’s obviously garbage. If it doesn’t show them, that still doesn’t mean it’s safe. The absence of visible mold is not a green light.
And if you do spot mold on one slice, don’t just cut it off or eat the other slices. Mold doesn’t only grow on the surface. Its filaments extend down into food, and the toxins mold produces can spread beyond the visible patch.
Reheating Won’t Fix It
A common assumption is that microwaving or oven-reheating old pizza kills whatever might be growing on it. This is partially true and partially dangerous. Reheating to a high internal temperature does kill most live bacteria. But certain bacteria, particularly Staphylococcus aureus and Bacillus cereus, produce toxins during their growth phase that are heat-stable. Once those toxins have formed in the food, no amount of reheating will destroy them. You could blast the pizza until the cheese is bubbling and still get sick from toxins that were produced days earlier while the pizza sat in your fridge.
This is why the storage timeline matters more than the reheating step. Reheating is a useful safety measure for pizza that’s 1 to 3 days old. It’s not a rescue strategy for pizza that’s been stored well past its safe window.
What Happens If You Eat It
Most people who eat slightly old food don’t end up in the hospital, and that experience creates a false sense of security. But the consequences of eating contaminated pizza range from mild to miserable. Symptoms typically include nausea, vomiting, stomach cramps, and diarrhea, and they can start anywhere from 1 to 6 hours after eating (for toxin-based illness) or 12 to 72 hours later (for bacterial infections). For healthy adults, this usually means a very unpleasant day or two. For young children, elderly adults, pregnant women, or anyone with a weakened immune system, the risks are more serious.
The tricky part is that eating old food sometimes causes no symptoms at all. That doesn’t mean it was safe. It means the bacterial load happened to be below the threshold that triggered illness that particular time. Playing the odds with 6-day-old pizza is a gamble with diminishing returns.
How to Store Pizza Safely
If you want your leftover pizza to last as long as possible within the safe window, get it into the refrigerator within 2 hours of being cooked or delivered. Store slices in airtight containers or wrap them tightly in aluminum foil or plastic wrap. Loose slices on a plate with no covering dry out faster and are more exposed to cross-contamination from other items in your fridge.
If you know you won’t eat the leftovers within 3 to 4 days, freeze them instead. Frozen pizza stays safe for 1 to 2 months with good quality, and technically remains safe indefinitely at 0°F, though texture and flavor decline over time. When you’re ready to eat it, reheat from frozen or after thawing in the fridge, bringing the internal temperature to at least 165°F.
Six days is too long. If you’re staring at nearly week-old pizza and debating whether to eat it, the safest call is to throw it out.