Missionary work of the Catholic Church has often been undertaken outside the geographically defined parishes and dioceses by religious orders who have people and material resources to spare, and some of which specialized in missions. Eventually, parishes and dioceses would be organized worldwide, often after an intermediate phase as an apostolic prefecture or apostolic vicariate. Catholic mission has predominantly been carried out by the Latin Church in practice.
In the Roman Curia, missionary work is organised by the Congregation for the Evangelization of Peoples.