Bratz: Forever Diamondz is a 3D game staring the Bratz girls, based on the 2006 direct-to-DVD film of the same name. The girls from Bratz magazine (Cloe, Jade, Sasha, and Yasmin) compete in a contest across the United States against the girls from Your Thing Magazine (Burdine, Kirstee and Kaycee) to find an undiscovered teen fashion designer for the 'America Rocks Fashion' TV show competition. The winner of the competition will then receive a contract with a famous fashion designer and a pair of go-go boots covered with diamonds.

In the game, you take control of one of the Bratz girls while exploring the towns you visit while searching for the teen designer. During the game, you switch between the girls and can customize their clothes, jewelry and makeup. The player will participate in photoshoots, ice skating and can adopt a pet.