Ash's starter Pokemon was going to be Clefairy but was swapped for Pikachu to make it appealing for boys and girls alike.
In December 1997, more than 700 Japanese children suffered seizures, vomiting, irritated eyes and other symptoms after viewing a flashing red background in the episode "Electric Soldier Porygon" from the Japanese version of the show. The show was pulled for retooling until April of 1998. "Electric Soldier Porygon" was only shown once (in Japan), and has never been shown again. The episode was dubbed for the American version with the offending animation slowed down and strobe effects deleted, but was never aired.
In the English dubbed version there have been notable fourth wall breaks by characters. In season 1 episode 26, when Gloom unleashes a foul odor everyone is repulsed, including Meowth. When Jesse points out that Meowth lacks a nose, Meowth says 'the cartoonist must have forgotten to draw it on!' Also, in season 1 episode 27, when Team Rocket attempt to steal Drowzee and Hypno using a convoluted mechanism which fails, they just grab them using whips. When Jesses asks why they didn't do that first, James says that they have to somehow make the show 30 minutes long.
Upon being told that Pokémon was going to be shown worldwide, director Masamitsu Hidaka decided to phase Brock out of the Orange Islands season, fearing American audiences would perceive him as a racist stereotype towards Asians. However, when his character received strong positive reception, he was brought back into the series.
The names of Jessie and James of Team Rocket were changed from their original Japanese names due to cultural reasons. In Japan, they are known as Musashi (Jessie) and Kojiro (James), which is a literary reference to two rival Samurai.