The gameplay in UFC 2009 Undisputed is focused on simulating the likeness of real-life UFC fights. Players can choose from three striking styles (Boxing, Kickboxing, Muay Thai) and three grappling styles (Wrestling, Judo, Brazilian Jiu-Jitsu), with each fighter carrying one style of each category.
The game features various modes to suit different player preferences. Exhibition allows players to jump straight into gameplay as their favorite fighter, while Classic Fights provides a chance to replicate memorable matches and earn unlockable montage videos. The Create-A-Fighter mode enables fans to build their own fighter, and with Career mode, players can upload their created fighter and build their career.