A commercial for the game features two sprites that went unused in the final game: an alternate ground tile and a symmetrically-spotted Poison Mushroom.

World 3-1's map data includes a Red Koopa Troopa inexplicably placed right above a pit, one space next to a ground tile. Because of its location, the enemy cannot be seen without the use of hacks or glitches, as the Koopa will have fallen into the pit by the time Mario reaches the spot where it spawns in. The enemy's unusual placement resulted in it going undiscovered until November 9, 2020, 34 years after the game's release.

Super Mario Bros. / Duck Hunt / World Class Track Meet has unused graphics from Super Mario Bros: The Lost Levels, which can be activated by a Game Genie code, allowing one to play SMB1 levels with The Lost Levels graphics, albeit with some glitched tiles in different parts of the game.

According to then Nintendo of America CEO Howard Lincolin, the game was not released overseas because it was too challenging and too much like the original to sell well. In order to prevent the early series from being associated with frustration and staleness, they instead adapted the Japan only game Doki Doki Panic, and released it as Super Mario Bros. 2 for the West.

Although Bloopers in Super Mario Bros. normally spawn only in water levels, they can be placed in non-water levels normally and will award a massive 1,000 points when stomped. Other "impossible" ways to kill enemies, such as hitting a Podoboo or Bowser with a Starman, only award the default 200 points. Given that Bloopers appear in non-water levels in Super Mario Bros.: The Lost Levels, and also award 1,000 points, this behavior was likely intended all along.

According to an interview with Shigeru Miyamoto in Family Computer Magazine, World 9 of Super Mario Bros.: The Lost Levels, which is only accessible by playing the entire game without using Warp Zones, is based on a glitch in the original Super Mario Bros., which could allow the player to access 256 extra worlds.

A special edition of Super Mario Bros.: The Lost Levels, entitled "All Night Nippon Super Mario Bros." was released only in Japan. It featured almost identical gameplay to that game and lifted level designs from Super Mario Bros., but instead replaced the enemies with Japanese celebrities. It was based on the popular Japanese radio program, "All Night Nippon", and was given away as a raffle prize from the program itself.