Which Pokémon anime episode aired once in Japan before a nationwide broadcast suspension?

The Pokémon anime episode that aired once in Japan before a nationwide broadcast suspension was “Dennō Senshi Porygon.”

The episode was broadcast on TV Tokyo on December 16, 1997, as the 38th episode of the first season. During a scene involving rapidly alternating red and blue flashes, many viewers experienced symptoms associated with photosensitive seizures. More than 600 people, mostly children, were taken to hospitals.

The incident led broadcasters to suspend the Pokémon anime in Japan while production and broadcast practices were reviewed. The episode was never rebroadcast and was removed from regular circulation. Although Porygon is named in the title, Pikachu’s attack causes the flashing explosion that is generally associated with the scene.

The event affected the franchise beyond television. Several planned episodes were delayed, and Pokémon’s producers introduced stricter visual guidelines for animated programming. The episode is commonly called “Electric Soldier Porygon” in English-language discussions, but its Japanese title is the canonical title used for the episode.