The first Catholic (Roman Catholic) missions were established on Woodlark Island in 1847 and Rooke Island in 1848. They closed in 1855 without having made any converts. The first successful missions were established by French missionaries belonging to the Mission of the Sacred Heart, in New Britain in 1882, and at Yule Island, northwest of Port Moresby, in 1885. The Society of the Divine Word began work in Madang in 1896, and the Society of Mary in the North Solomons in 1897. By 1907 the Yule Island mission had extended its influence to the mainland coast and claimed over 4,000 adherents, including seven Papuan catechists. In 1915 the church established its headquarters in Port Moresby.
When the Australians formally took over the German colony of New Guinea in 1921, Catholic missionaries from Germany were active in New Britain, New Ireland, Bougainville Island and Madang. In 1928 Catholics extended their influence in the Sepik area and in 1933 Divine Word missionaries were among the first whites to enter the highlands. By 1942 the three missionary orders claimed that there were 160,000 Catholics in the Mandated Territory when the total number of Christians was estimated at 400,000. Missionary activity was disrupted by World War II and a number of missionaries lost their lives. After the war the Catholic missions were reestablished and their influence extended to other parts of the country. The Catholics were slow to train PNGans as priests. Although the first PNGan priest was a Catholic (1937), at Independence in 1975 the majority of the priesthood was still made up of expatriate Australians, Europeans and North Americans.
The Catholic church now has the largest number of adherents of any Christian denomination. In 1990 the 1,023,139 Catholics were 29.4 percent of Christians and 28.4 percent of the total population. There are four archdioceses and 14 dioceses and the majority of church workers are PNGan. The church is the most important non-government provider of education and health services. In 1991 the church ran approximately one quarter of the primary schools, one fifth of the post-primary schools and a number of health centers. The Catholic church is a member of the Papua New Guinea Council of Churches.