According to government statistics, 42.6 percent or more than 17 million of South Korea's 1985 population professed adherence to an organized religious community. There were at least 8 million Buddhists (about 20 percent of the total population), about 6.5 million Protestants (16 percent of the population), some 1.9 million Roman Catholics (5 percent), nearly 500,000 people who belonged to Confucian groups (1 percent), and more than 300,000 others (0.7 percent). Significantly, large metropolitan areas had the highest proportions of people belonging to formal religious groups: 49.9 percent in Seoul, 46.1 percent for Pusan, and 45.8 percent for Taegu. The figures for Christians revealed that South Korea had the highest percentage of Christians of any country in East Asia or Southeast Asia, with the exception of the Philippines.

Except for the Christian groups, who maintain a fairly clearcut distinction between believers and nonbelievers, there is some ambiguity in these statistics. As mentioned above, there is no exact or exclusive criterion by which Buddhists or Confucianists can be identified. Many people outside of formal groups have been deeply influenced by these traditions. Moreover, there is nothing contradictory in one person's visiting and praying at Buddhist temples, participating in Confucian ancestor rites, and even consulting a shaman and sponsoring a kut. Furthermore, the statistics may underrepresent the numbers of people belonging to new religions. Some sources have given the number of adherents of Ch'ondogyo as over 1 million.

Given the great diversity of religious expression, the role of religion in South Korea's social development has been a complex one. Some traditions, especially Buddhism, are identified primarily with the past. Buddhist sites such as the Pulguksa Temple and the Sokkuram Grotto in Kyongju and the Haeinsa Temple near Taegu are regarded by most South Koreans as important cultural properties rather than as places of worship. Confucianism remains important as a social ethic its influence is evident in the immense importance Koreans ascribe to education. Christianity is identified with modernization and social reform. Many Christians in contemporary South Korea, such as veteran political opposition leader Kim Dae Jung, a Catholic, have been outspoken advocates of human rights and critics of the government. Christian-sponsored organizations such as the Urban Industrial Mission promote labor organizations and the union movement. New religions draw on both traditional beliefs and on Christianity, achieving a baffling variety and diversity of views. It has been estimated that there were as many as 300 new religions in South Korea in the late 1980s, though many were small and transient phenomena.

Data as of June 1990