Using a glitch to get under DK Isle, going towards the waterfall will bring you to the escape ship cockpit King K. Rool used during the "K. Rool Press Button" cutscene.

It was originally believed that the only reason the game needed the Expansion Pak to run was because it fixed a game-breaking bug that caused the 4 megabyte game cartridge to randomly crash. Rare couldn't find any other solution, so they bundled the Expansion Pak with the game, costing them a lot of money. They still don't know what caused the bug. According to software engineer Chris Marlow:


However, developer Mark Stevenson claimed that while there was a game-breaking bug, it only affected one hardware revision of the Nintendo 64 that would be resolved on later models. He claims that the actual reason the Expansion Pak was required was because Rare's management instructed the game's developers to support it early in development to accommodate advanced graphical effects like dynamic lighting. Stevenson speculated that these two stories were likely conflated into one, creating the memory leak rumor that persisted for years.

Ultimately, Simon Craddick, one of the four engineers who worked on the Expansion Pak's implementation into Donkey Kong 64, claimed in a Facebook group that the only thing the Expansion Pak actually did was add vertex lighting to the levels.

Early screenshots of Donkey Kong 64 showed that Donkey Kong's Treehouse originally had a shower stall in it with a poster of Banjo and Kazooie on it.

Grant Kirkhope, composer for the game, provided the voice of Donkey Kong.

Despite being an E-rated game, the intro got away with mild swearing. Near the end of the song, the last line during Chunky Kong's portion of the song says, "But this kong's one hell of a guy". The game was developed by Rare, a British company, and in Great Britain the word isn't considered offensive. In later versions of the song the word is replaced with "heck".

The xylophone that appears in Candy's Music Shop is the same xylophone that Mumbo plays in the intro to Banjo-Kazooie.

In Donkey Kong's cabin hangs a picture of a dolphin. This is a reference to the code name of the Nintendo Gamecube, "Dolphin". The game was released before the Nintendo Gamecube was revealed, and is thought to be the earliest reference to the code name "Dolphin."