The Holy See established Kompong Cham as an Ecclesiastical Circumscription on Sept. 26, 1968.
The prefecture covers seven provinces: Kompong Cham, Kratie, Stung Treng, Rattanakiri, Mondolkiri, Svay Rieng and Prey Veng. Its first Apostolic Prefect was Monsignor Andre Lesouef.
All Church work was destroyed during the civil war. Many priests and Christians were killed in 1970-1979.
In 1993, Monsignor Lesouef came to Kompong Cham. He stood in front of the Kompong market for a whole day, hoping to find a single Christian there, but he failed. After returning to Phnom Penh, he received a letter from a young Catholic woman from Kompong Cham. He came to meet her and from then he started his missionary work in the prefecture.