There are 2 games for the PSP that we can find and they are called the Naruto: Ultimate Ninja Heroes and Naruto: Narutimate Hero Portable below is a little run down about these to brilliant Naruto PSP games plus a couple of links of where you can buy them from.

Naruto: Ultimate Ninja Heroes PSP Game
Developed by CyberConnect2 exclusively for the U.S. and Europe, Naruto: Ultimate Ninja Heroes gives gamers the ability to sharpen their ninja skills with intense single and multiplayer team-based fighting. In a new addition to the franchise, gamers will also have the ability to create and customize their own ninja dream squads to battle opponents or trade players’ profiles via wireless connectivity. To further maximize the character power-up feature, players can form different team combinations to awaken hidden skills that lie within each group. Depending on the combinations, special team-based skills can be unleashed. Gamers can also earn power-up points toward upgrading each character’s attack, defense, chakra, speed, and even special abilities.

Naruto: Narutimate Hero Portable PSP Game
A PSP entry in the Narutimate Hero series of Naruto games. Namco Bandai later introduced a brand new Naruto to the PSP in 2007. This is a U.M.D. based game and, therefore, is region-free and may be played any PSP from around the globe. It is based on the popular manga and anime series Naruto by Masashi Kishimoto. The game features 23 characters, 10 different stages, and the characters’ original combos and grab attacks.