What was the name of the Japan-only 1998 Nintendo 64 predecessor to Pokémon Stadium?

The Japan-only 1998 Nintendo 64 predecessor to Pokémon Stadium was Pocket Monsters Stadium.

Pocket Monsters Stadium was an early 3D Pokémon battle game released only in Japan. It was followed by the 1999 Nintendo 64 title Pokémon Stadium, which was released internationally and became the better-known entry in the series.

The Japanese predecessor was more limited than the later game. It originally focused on a smaller selection of Pokémon, while Pokémon Stadium expanded support to all 151 species from Pokémon Red, Blue, and Yellow. The international release also included features such as compatibility with Game Boy Pokémon through the Transfer Pak.

The naming can be confusing because the Japanese Pokémon Stadium is effectively the second Stadium title in the series. In Japan, the 1999 game was initially presented as Pokémon Stadium 2, while Western releases called it Pokémon Stadium. Therefore, “Pocket Monsters Stadium” identifies the Japan-only 1998 predecessor, not the internationally released 1999 game.