In a land area of 5,955 square kilometers, the diocesan territory covers Dong Nai province and Binh Duong province's Di An district. It is bounded on the north by Phu Cuong diocese; on the east by dioceses of Da Lat and Phan Thiet; on the south by Ba Ria diocese and on the west by Ho Chi Minh City archdiocese. Bien Hoa city, the first class and capital of Dong Nai province, is an industrial center surrounded by many foreign and domestic factories and warehouses. In 2010, it has a population of 784,000 and a land area of 264.08 square kilometers. It has a population density of 2,969 people per square kilometer.
In 2017, the diocese had a total population of 3,269,900, including ethnic minority groups of Cho ro, Khor, Ma, Stieng and Tay.
Vietnamese is mainly used in the diocesan territory. Ethnic languages are also in use within ethnic minority communities.
The origin of the Xuan Loc diocese goes back to first Catholics from central and northern Vietnam who escaped from religious persecution by soldiers at the end of the 17th century. Foreign Jesuits provided pastoral activities for them. At the same time, other people moved to the south during kings' campaigns to expand southern territories for centuries.
During the 1954 exodus, tens of thousands of Catholics from northern dioceses fled to the area to avoid communists. They formed Catholic villages in the province.
Xuan Loc diocese was separated from Sai Gon (now Ho Chi Minh City) archdiocese and established on Oct 14, 1965. Bishop Joseph Le Van An (1965-1974) was named the first prelate of the diocese. At its establishment, the diocese had 164,144 Catholics among a total population of 521,595, served by 154 priests and 250 Religious.
Bishop An built the Bishop's House and minor seminary.
The diocese's activities were limited after 1975, when the country was reunified under commuist rule.
Bishop Paul Nguyen Minh Nhat (1975-2004) issued new seminarian formation programs and restructured activities of lay associations and parish councils. The local Church also published catechism books that have been used by other dioceses so far.
Bishop Dominic Nguyen Chu Trinh, the fifth prelate of the diocese, built the new complex of Bishop's House, Pastoral Center and Major Seminary in 2009.
The major seminary gives priestly formation to students from Xuan Loc and its three neighboring dioceses of Ba Ria, Da Lat and Phan Thiet.
The diocese now aims to strengthen values of family and gives regular training courses to local clergy. It also provides vocational skills and scholarships for poor young people. Its top priorities are to build churches in remote areas and send lay missioners to areas without resident priests.
The diocese is suffragan of Ho Chi Minh City archdiocese.
Main transport is train, buses, motorcycles, bicycles and boats connecting Bien Hoa city to other provinces and Ho Chi Minh city.
The diocese has a tropical climate and features in two seasons - rainy season lasting from May to November and dry season lasting from December to April. It has an average annual temperature of 25-27 degrees of centigrade.
Local people mainly work as farmers who grow rice, rubber trees, fruit trees and others. Some raise shrim, crap and oyster. Other people work for domestic and foreign companies. Some villages make wood furniture. Dong Nai province is known for its large production of various kinds of fruit trees such as rambutan, durian and pomelo.
In 2010, the annual per capita income of people in rural areas is 18,720,000 dong (US$960 as of November 2010) and income of people in urban areas is 24,960,000 dong (US$1,280 as of November 2010).
The diocese has Buddhists, Muslims, Protestants and followers of indigenous Cao Dai and Hoa Hao. Hoa Hao Buddhist sect has a large propotion of followers. Many of them work with Catholic priests to build bridges over rivers in remote areas.