If you are storing meatballs to consume them soon, it is recommended that you put them in an airtight container with a lid or a plastic wrap, and store in the refrigerator. It would be good not to leave cooked meatballs at room temperature for more than 2 hours so that bacteria do not start to develop. You can store meatballs in the refrigerator for up to 4 days. For more extended storage, be sure to put them in the freezer immediately, as this will extend their shelf life up to 3 or 4 months.