Yes. Oreos balls need to be kept in the refrigerator after they are made. Since they are covered in white chocolate and have cream cheese in them, they need to be stored in the fridge. They can be left out on the counter or outside for your cookout or BBQ, but just be aware the white chocolate may get a little melty if it's hot or has been a while. If this happens, popping the freezer or fridge will harden them right back up! They freeze excellently too if you would like! You can make these ahead of time and store them in the freezer for up to 6 months (in an airtight container). Or make them and store them in the freezer and eat straight from there. They won't freeze solid and honestly, I prefer them frozen. They are delicious!