Family name Kamsai (Kamsai 
) , all over the world, is a rare surname. The family name Kamsai is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname, Malaysia, where it is a very rare surname, and Philippines, where it is an extremely rare surname. Measured by absolute frequency, it most frequently occurs in Thailand, India, and Malaysia. Much less frequently, Kamsai is the forename as well as the last name.