The following are known Action Replay Codes for MLB 98 on Sony Playstation (PS1).

The codes should work with the region specified but may work for other regions as well.

Device Compatibility: Action Replay, CodeBreaker & GameShark

Home Team Scores 50
800121b43232

Away Team Scores 50
800121f63232

Away Team Scores 0
800121f60000

Home Team Scores 0
800121b40000