 It was upgraded to a full district on 17 July 1963.Lahan Sai means "plain fertile width hog deer" ("Axis porcinus").Neighboring districts are (from the southwest clockwise) Ta Phraya of Sa Kaeo Province, Non Din Daeng, Pakham, Nang Rong, Chaloem Phra Kiat, Prakhon Chai, and Ban Kruat of Buriram Province.