The apostolic vicariate of West Timor was erected on May 25, 1936, with Divine Word Father Jacobus Pessers as its first apostolic vicar. He was ordained a bishop on June 16, 1937. Atambua became the center of the apostolic vicariate. Catholics numbered about 42,000 in West Timor, served by 19 Divine Word priests, three brothers, and 12 Servants of the Holy Spirit sisters.
On Jan. 28, 1941, the Catholic Church in Timor was blessed with the ordination of its first son, Father Gabriel Manek, who later became apostolic vicar of Larantuka and then archbishop of Ende. He was born in Lahurus.
The name of the vicariate waschanged to Atambus in 1948, and two years later, on Sept 8, 1950 and it established its minor seminary in Lalian, 9 kilometers south of Atambua. In 1957, the Divine Word Society Timor region set up the St. Joseph Formation House to train Timorese youths who wanted to become religious brothers.
Atambua became a diocese on Jan. 3, 1961. Its first diocesan priest was ordained five years later. On Aug. 15, 1967, Atambua diocese was divided in two, one of the halves becoming Kupang diocese, which was elevated to an archdiocese in 1989.