In 1848 the Catholic Church was called the “Vicariate of Melanesia” which included all the islands of Melanesia and Micronesia. The Catholic Church grew rapidly in different parts of PNG. On 15 November 1966 the Hierarchy of Papua New Guinea was established with Archdiocese and Dioceses. The Catholic Bishops Conference has 19 Dioceses in Papua New Guinea and 3 Dioceses in Solomon Islands with a total of 23 Bishops.

PNG Dioceses: 1. Vanimo, 2.Aitape, 3. Wewak, 4. Madang, 5. Lae, 6. Wabag, 7. Kuniawa, 8. Mendi, 9. Goroka, 10. Mt. Hagen, 11. Kavieng, 12. Rabaul, 13. Kimbe, 14. Buka, 15. Alotau, 16. Port Moresby, 17. Berena, 18. Kerema, 19. Daru/Kiunga.
Solomon Islands Dioceses: 1. Auki, 2. Gizo, 3. Honiara

The Catholic Church is the largest Non-Government body to provide services – including education and health care – in Papua New Guinea.

The office of the first Catholic Bishops Conference in 1966 was at the residences of the Priests who were the General Secretaries. The First General Secretary with a structured office was Fr. Dennis Rochford, MSC in 1983. The first buildings housed CBC, Caritas offices and one residential building. Many Commissions of the CBC were operating from Port Moresby, Goroka, Rabaul or other cities as the need arose. As more offices were needed, additional buildings were added in 2000.