Cambodia's Muslims are descendants of Chams who migrated from what is now central Vietnam after the final defeat of the kingdom of Champa by the Vietnamese in 1471. Like their Buddhist neighbours, however, the Cham Muslims call the faithful to prayer by banging a drum, rather than with the call of the muezzin, as in most Muslim lands.

The Khmer Rouge made a concerted effort to discriminate against Cambodia's Cham Muslim community. Muslims were forced to eat pork, even when other Khmers were deprived of meat, and many were singled out for execution for simply refusing to do so.