Last name ประศาสน์ (Prasat 
, ประศาสน์ ) , worldwide, is a rare surname. The family name ประศาสน์ is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname, Myanmar, and Malaysia. Measured by absolute frequency, this name is the most popular in Thailand, India, and Myanmar. More frequently, ประศาสน์ is the forename as well as the last name.