Banana Medals are special items that appear in Donkey Kong 64.
Banana Medals can be obtained after collecting 75 regular bananas for a Kong in each level (except for DK Isles and Hideout Helm). That means that 5 Banana Medals can be obtained per stage. Although it seems they serve no purpose at first, it is revealed that at least 15 Banana Medals is needed to play Cranky Kong's Jetpac game in order to get the Rareware Coin which is needed to compete the game. At Hideout Helm, Banana Medals can be obtained after a Kong completes his/her mini-games.