The series originated from 'All Growed Up', a 2001 TV special celebrating Rugrats' 10th anniversary that depicted the original toddler characters ten years into the future.

'All Growed Up' was the highest-rated Rugrats episode ever and cable's No. 1 show for the week ending July 22, 2001, drawing a 7.2 rating equivalent to about 12 million viewers, with roughly 70% of kids aged 2–11 tuning in.

After witnessing the special's massive popularity, Nickelodeon executives declared 'We've got to make this a show' and ordered a two-season run of 35 episodes.

The show's format changed from the original Rugrats' two 11-minute stories per episode to a single 22-minute story per episode, giving writers more time to develop character arcs.

The visual style evolved gradually over the first three seasons: the first 15 episodes resembled the original 'All Growed Up' special's look, while later episodes gave the characters more contemporary, 'hipper' clothing.

The returning voice cast had to modify their vocal performances to match the characters' new ages, with actress E.G. Daily noting it was challenging in early episodes to redefine how each character had grown.

Rapper Lil Romeo guest-starred as a character called 'Lil Q' (Cupid) in the season 1 episode 'It's Cupid, Stupid,' one of the show's only celebrity guest appearances.

Rugrats co-creator Paul Germain, who had left Klasky Csupo in 1993, publicly disliked All Grown Up!, arguing that since Rugrats was about babies misunderstanding the adult world, aging the characters into teenagers effectively ended the original premise.