As of 2001[update] India census, Nongstoin had a population of 22,003. Males constitute 50% of the population and females 50%. Nongstoin has an average literacy rate of 67%, higher than the national average of 59.5%: male literacy is 67%, and female literacy is 66%. In Nongstoin, 23% of the population is under 6 years of age.
In January 2006, Pope Benedict XVI erected a diocese in Nongstoin, covering the West Khasi Hills district. The Franciscan Missionary Brothers of the Catholic Church run a College and a School at Siejlieh, Nongstoin