The Minus World glitch is believed to be first acknowledged by Nintendo in the third issue of Nintendo Power (November/December, 1988, page 55).

According to Super Mario Bros. Wonder's art director Masanobu Sato, Shigeru Miyamoto reportedly explained during the development of the first Super Mario Bros. that the reason why Goombas damage Mario when walking into them is because they bite Mario on impact. Due to graphical and hardware limitations, this could not be shown at the time. However, while Super Mario Bros. Wonder is thought to be the first game in the mainline series that shows this detail in gameplay, it's not the first game in the overall franchise to show it, as Goombas had been seen biting in earlier spin-off games like Super Mario RPG: Legend of the Seven Stars.

According to Pac-Man creator Toru Iwatani, Pac-Land had a strong influence on the development of Super Mario Bros. In an interview with Geek Culture, Iwatani stated:

According to source code leaked in 2020, during development of Super Mario Bros., Bowser was called "Big tortoice" [sic]

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.

During the development of Super Mario Bros., a 16x32 pixel square represented the player character. After asking to see sales figures from the head of Nintendo's Sales and Marketing Division, Takashi Tezuka and Shigeru Miyamoto decided to make Mario the game's protagonist due to the success of the Famicom port of Mario Bros.

The South African release of Super Mario Bros. (included as a pack-in title for the Nintendo Entertainment System in the country) reuses its packaging from the European edition, with the only difference being its unique serial code, NES-SM-GPS. Notably, this is the only South African NES game which does this, as other releases there are explicitly marked for the region on the box art and cartridge label.

Super Mario Bros. was originally planned to have an "air, land, and sea" concept. While the player normally runs on solid ground and swims underwater in certain levels, designer Takashi Tezuka explained in interviews that Mario would have been able to fight in the air while riding in a cloud. Instead of creating more brand new air-based enemies, they attached wings to an existing enemy to save on memory, resulting in the creation of the Koopa Paratroopa. However, the trial demo created to test these levels was deemed not fun to play, feeling more like a shoot 'em up game than what they were hoping. On top of this, the levels were deemed to be contributing to the memory constraints, leading to their removal. However, Tezuka strongly felt the game should still have air-based levels, leading him to suggest an idea to director Shigeru Miyamoto inspired by the fairy tale "Jack and the Beanstalk", where Mario could climb a vine from a Question Mark Block into the clouds, allowing players to collect coins in certain levels. Miyamoto liked the idea, and subsequently created the vines and constructed the game's bonus areas from existing elements. The "air, land, and sea" concept and Mario's ability to fight while in the air or clouds would be added in subsequent games in the series.