Roasted nuts can last for a few weeks up to a few months, depending on various factors such as the type of nut, storage conditions, and whether or not they are shelled. It is best to store them in an airtight container in a cool, dry place, away from direct sunlight and moisture. Roasted nuts with high oil content, such as macadamia nuts and pecans, tend to spoil faster than those with lower oil content, such as almonds and walnuts. It is always a good idea to check for any signs of spoilage, such as off odor or flavor, mold, or discoloration, before consuming roasted nuts that have been stored for a while.