The following are known Action Replay Codes for Yu Yu Hakusho – Ghost Files: Tournament Tactics on Nintendo Game Boy Advance (GBA).
These codes were also known as GameShark Codes and in most cases will work on both devices.

These codes are for the U.S. version of the game.

Master Code – Must Be On
9edaed16
1ba3faa2
3c121e0f
4a50d751

Infinite Upgrade Points
e18ed2a2
b31a352c
Note: Do not use this on the first mission.

Have All Levels Unlocked
6488722e
968652b3
8cad51ff
e6a1e793
abe54a0f
ab9da758

Yusuke: Quick Level Up
4e1f892b
53c918fb

Kuwa: Quick Level Up
a3140682
918b5522