Before the government's campaign against religion in the 1930s, there were about 700 monasteries, with about 100,000 lamas (theoretically celibate), in Mongolia. During 1936–39, the Communist regime closed virtually all monasteries, confiscated their livestock and landholdings, tried the higher lamas for counterrevolutionary activities, and induced thousands of lower lamas to adopt a secular mode of life. In the mid-1980s, only about 100 lamas remained. The new constitution of 1992 established freedom of religion for all. Mahayana Buddhism, the primary religious following before the suppression of religion in the 1930s is making a surprising resurgence. Former monasteries are being restored, and there is a seminary at Gandantegchinlen Hiyd. In 1992, Roman Catholic missionaries were also encouraged to come to Mongolia to continue the presence they had initiated earlier in the century.
A 2002 report indicates that about 93% of the population practice some form of Buddhism, mostly Lamaist (or Tibetan) Buddhism. About 4% of the population are ethnic Kazakh Muslims. There are small Christian communities throughout the country and it is believed that some natives practice shamanism.