Which episode of the Pokémon TV series caused a worldwide broadcast health incident involving flashing lights?

“Dennō Senshi Porygon” caused the worldwide broadcast health incident involving flashing lights in the Pokémon TV series.

The episode aired in Japan on December 16, 1997. Rapid red-and-blue flashing effects during an explosion sequence were associated with seizures and other symptoms among viewers, particularly children. Japanese broadcasters and production authorities responded by withdrawing the episode from circulation and reviewing broadcast practices.

The incident had consequences for the Pokémon anime’s international release. “Dennō Senshi Porygon” was never officially broadcast outside Japan, and the series underwent changes to reduce the risk of photosensitive reactions. The episode is commonly known in English as “Electric Soldier Porygon.”

A common misconception is that Porygon itself caused the problem. The reported trigger was the flashing visual sequence, and Pikachu appears during that scene. Because of the controversy, Porygon and its evolutions became much less visible in later anime stories than their prominence in the games might suggest.