Prior to 1924 this territory formed part of the Kimberly Vicariate. From 1924 it was known as the Kroonstad Vicariate. Msgr. Leo Klerlein CSSp was appointed Prefect Apostolic in 1924, Vicar Apostolic in 1935. By Papal Decree dated 12 February 1948, the Sacred Congregation of Propagation of the Faith partitioned the Kroonstad Vicariate into two separate Vicariates. The western part with Kroonstad was entrusted to the Dominican Fathers of the Dutch Province. The eastern part with Bethlehem was entrusted to the Holy Ghost Fathers (CSSp) of the German Province. Msgr. Klerlein retired in 1948, with the creation of the new Vicariate. He was succeeded in 1950 by Bishop Peter Kelleter CSSp, who resigned on 5 July 1975.
The diocese comprises the following magisterial district: Bethlehem, Clocolan, Ficksburg, Fouriesburg, Frankfort, Harrismith, Lindley, Reitz, Senekal, Vrede, Phuthaditjhaba (Qwaqwa), and part of Ladybrand.