Bruno's Pokéball at the start of the episode is green, instead of the normal red.
Ash is based off of Red, a character from the Pokémon Adventures manga and main character of the Red, Green, Blue, and Yellow video games.
Pikachu's Pokéball has a lightning bolt on it.
Pikachu is the first Pokémon that willfully disobeys Ash in the series. However, the disobedience ends at the end of the episode.
The shadowed trainer shown at the very beginning with the Nidorino and Onix was Bruno. It is rumored the Gengar's trainer is Agatha. The opening battle is also the same opening from Pokémon: Red Version.
The bird Ash saw at the end of the episode was Ho-oh. This makes it the first Johto Pokémon seen in the series though it had no name at the time
Ash has a Voltorb Clock.
If Professor Oak was supposed to give 4 trainers Pokemon, he should have more than 3 available (at least as far as everyone knows).
Gary: Hey, watch where you're going! Well, you must be Ash. Better late than never, I guess. At least you get the chance to meet me!
Why would Gary, who should be Ash's lifelong rival, say something like that? It sounds like Gary had heard all about Ash from some other people and this was the first time they met.
When Ash enters Professor Oak's Lab and looks at the Pokéballs, the writing is Japanese. When Ash picks up a Pokéball, it's not in Japanese. Later in the series, regular Pokéballs never have writing on them.
Also, the Pokéballs for the three starters shouldn't have been there at all because the Pokémon had already been chosen.
Ash: (To Pikachu) Pikachu, get inside the Pokéball. I know you're afraid of going in there, but if you're inside maybe I can save you. Please Pikachu. After that then...after that...just trust me!
Narrator: This is just the beginning of the amazing adventures of Ash and Pikachu. Their journey is destined to be packed with non-stop action, millions of laughs, heart pounding perils and endless excitement. Together they will encounter fantastic friends, evil enemies and meet creatures beyond their wildest imagination and as their story unfolds, we'll unlock the magic and mystery of the most wondrous place: the incredible world of Pokémon!
Ash: Professor Oak? Where's my Pokémon?
Oak: Your Pokémon?
Ash: Yeah. I'm ready.
Oak: You look more like you're ready for bed, not for Pokémon training. I hope you're not going to train in your pajamas.
Ash: Hey, get out of there! (Rattata runs away from his backpack.)
Pokédex: A forest Pokémon - Rattata. It likes cheese, nuts, fruits and berries.
Ash: Yeah, but this isn't a forest, it's an open field.
Pokédex: It also comes out in open fields to steal food from stupid travelers.
Ash: So that means I'm stupid?
Pikachu: (Laughs) Pika... Pika!
Misty: Are you okay?
Ash: Yeah, I'm fine...
Misty: (walks up to Pikachu) I meant your Pokémon!
(Ash looks at the sky and sees Ho-oh)
Ash: I wonder what that is?
Pokédex: There is no data. There are still Pokémon yet to be identified.
Although this season did not have a subtitle at first, it was later given the subtitle "Indigo League" on DVD boxsets.
In the English dub, after Ash says "Yeah, I'm okay..." to Misty, the scene freezes. Then Misty says "Not you!" during that frozen scene. This is because a scene of Misty slapping Ash is cut out of the dub.
This episode was published in the book Pokémon Volume 1 "I Choose You".
The Japanese title is kept.
When this episode was originally going to be created, Ash's starter was going to be a Clefairy.
This episode is on the VHS/DVD I Choose You! Pikachu!
This is the only episode without Team Rocket in it at all until Season 8 (though the Season 8 episode was not dubbed). However, beginning with Season 14 they start not appearing in every episode.
Pokémon Debuts: Gengar, Nidorino, Onix, Dodrio, Pikachu, Rattata, Pidgey, Spearow, Sandshrew, Mankey, Gyarados, Ho-Oh, Magikarp, Voltorb.
Who's That Pokémon: Pikachu
Character Debuts: Ash, Professor Oak, Delia, Misty, and Gary.
The Japanese names for Ash (Satoshi) and Gary (Shigeru) have some significance. Ash's Japanese name was named for the creator of the Pokémon games: Satoshi Tajiri. Gary's Japanese name, Shigeru, was named for the creator of the Mario games, Shigeru Miyamoto. This was meant to be an inside jab indicating that Pokémon rivaled Mario as the top character/game series from Nintendo.