Southeast Asia is known as one of the main lands of Islam. The number of believers in the region accounts for 60% of the total populations. In Indonesia, it is 85%, Brunei 65%, Malaysia 55%, Singapore 17%, the Philippines 8%, Cambodia 7%, Myanmar 5%, Thailand 4%. Yet, in Vietnam Muslims account for only a small percentage.

         As early as the 11th and 12th centuries, Arabian and Indian traders brought Islam to Southeast Asia via business contacts. The new religion was later mixed with local beliefs and customs. In Vietnam, its emergence coincided with the decline of the Chiêm Thành Dynasty in the 15th century. However, according to the Chinese Song historians, the religion was present in Vietnam during the turn of the 10th century to the 11th century.

         In Vietnam, Islam is practiced mostly by the Cham people (50,000 adherents), who concentrate in Ninh Thuan, Binh Thuan, An Giang, Sàigòn, Tây Ninh and Dong Nai.

         According to legend, the Cham people, whose indigenous religion was Brahmanism, first familiarized themselves with Islam around the 10th and 11th centuries. But this religion became more visible only when the Chiêm Thành empire declined in the 15th century, which caused a massive migration of the Cham to Cambodia.

         After regular contacts with Malaysian Muslims, the Cham immigrants soon became converted to Islam. Furthermore, later, they tried to encourage their compatriots in Central Vietnam to follow them but their effort was not much successful as there were in the Cham community at the time heavy vestiges of matriarchy. Consequently, the Cham were divided into two main groups: Islamic and Brahminic followers.

         In the 18th century, the Nguyen Court's army led by Truong Minh Giang, the protector of Chenla (Chân Lap) was driven back to Châu Dôc (a province of Viêtnam) in a battle with An Duong and his Cambodian soldiers. Among the former were the Cham and Malaysian Muslims, who started settling in this region. Later, they were joined by the Malaysians and the Cham who had participated in an unsuccessful uprising led by Tuôn Sêt It (1854-1857) to counter Chenla Kingdom. Thus Châu Dôc became the 2nd region of Muslims in Viêtnam.

          Different factors account for the birth of different Islamic groups. The group in Tây Ninh was founded in the 18th century by two leaders who had escaped from Cambodia. The group in Sàigòn appeared during the French domination as the result of migration into the City. The group in Dông Nai came into being when the Republic of Viêt Nam regime pursued the policy to "disperse" the populations towards the suburbs to prevent the deep penetration of the Liberation forces.

          Such factors as geographical conditions, circumstances of the diffusion of the religion, living conditions and extents of communication with the outside world helped to form two main groups of Vietnamese Muslims:

           1. The Cham Muslims in Binh Thuan and Ninh Thuan constitute the non-Orthodox Islamic group (or Cham Ba Ni).

           2. Those in Chau Doc (An Giang) ,Sàigòn, Tây Ninh and Dong Nai constitute the Orthodox Islamic group (Cham Islam).