Pradal Serey, or Khmer Boxing, means "free fighting style" in Khmer language. It is believed to be the oldest of South East Asia's ancient martial arts. Bas-reliefs at the Bayon, in the ancient city of Angkor, show Khmer soldiers displaying combat techniques involving knees, elbows and kicks. Even though any written record of Khmer boxing had been lost for centuries, it is believed by the Cambodians that this was the army's standard combat style at the time of the Khmer Empire's maximum expansion (9th century AD).

Pradal Serey, or Khmer Boxing, means "free fighting style" in Khmer language. It is believed to be the oldest of South East Asia's ancient martial arts. Bas-reliefs at the Bayon, in the ancient city of Angkor, show Khmer soldiers displaying combat techniques involving knees, elbows and kicks. Even though any written record of Khmer boxing had been lost for centuries, it is believed by the Cambodians that this was the army's standard combat style at the time of the Khmer Empire's maximum expansion (9th century AD).

Khmer boxing was on the verge of extinction, together with all forms of Khmer culture, during Pol Pot's Khmer Rouge regime (1975-1979). In order to rapidly create a new, ultra-Maoist society based on an Utopian, agricultural life as in the centuries before, the Khmer Rouge announced Year Zero and systematically destroyed the country's infrastructure. All "enemies of the revolution" were executed. These included teachers, aristocrats, educated people, monks, doctors, artists, foreign speaking Cambodians, actors, singers and Khmer boxing practitioners. Everybody else was sent for re-education to labor camps upcountry, which later became sadly known as the "killing fields". Millions died of starvation, diseases and summary executions. A big portion of the centuries-old Khmer cultural heritage, including pradal serey and its teachers, disappeared in only four years.

Following the country's slow recovery from the 20 years-old civil war that erupted after the Khmer Rouge were ousted by the Vietnamese in 1979, Khmer boxing slowly resurfaced in small, private schools in Phnom Penh. Far from being commercial operations, such schools were created by survivors, to pass whatever was left of pradal serey to the new generations, thus keeping the country's heritage alive. Since 2003, Khmer boxing has been officially supported by the Government as an important part of the Khmer heritage and it's attracting a growing number of young athletes. Professional fighters now earn a living from sponsorships and cash prizes, but they're far behind their Thai counterparts in terms of income. On average, a professional Khme boxer earns 20 USD a fight, plus some goods from the sponsors, mostly Thai-based companies already involved in muay thai events in Thailand.

Cambodian authorities have been very vocal about the history of their native martial art, especially with their Thai neighbors. Whilst pradal serey was already around approximately one thousand years ago, no such thing as muay thai, or even muay Siam, was recorded at the time. Moreover, they argue that when the Khmer empire collapsed in the 12th century AD and Angkor was abandoned to the jungle, Siamese intruders captured Khmer soldiers and assimilated their captives' fighting style into their own army's standard. Thus pradal serey is, according to Cambodians, the true ancestor of muay boran and so of muay thai! Don't tell this to a Thai, though...

From a spectator's point of view, pradal serey appears very, very similar to muay thai. In truth, many techniques derived from muay boran are actually known and permitted in muay thai professional bouts, but they are very rarely implemented. Cambodian fighters instead rely much more on elbws and knees, often performing stilish and graceful moves reminding of muay boran forgotten moves. Khmer boxing is exciting to watch, as it's faster and more technic than muay thai, without the brutality proper of Let Wei. Nowadays Pradal Serey has its own boxing circuit and fights are televised on Cambodian Channel 3 and 5 on weekends.