This work explored the Phu Tai language use in ritualistic healing of the Phu Tai ethnic group residing in three villages, namely Kham Cha-ee in Tambon Kham Cha-ee, Nong O in Tambon Non Yang, Kham Cha-ee District, Mukdahan Province, and Renu in Tambon Resu, Renu Nakhon District, Nakhon Phanom Province. It was found from the investigation that different types of folk healers used different varieties of the language. For instance, an obstetrician used simple, easy-to-understand and everyday-life language. A midwife mainly used Pali and Sanskrit while a spiritual healer (Mor Jod, Mor Pau) used Khmer, Pali and Sanskrit. A shaman (Mor Tham) used different varieties of impolite language because he had to fight with evil spirits. Another kind of shaman, Mor Yau, used a polite and pleasant variety because he had to seek mercy from spirits to heal sicknesses. The language use of these healers was mostly in a poetic, pleasant form with rhyming. Sometimes, an archaic and difficult form of Phu Tai was used, based on a belief that a difficult-to-understand form of the language created a sense of grandeur and trust.