The local inhabitants of Lachung are either of Tibetan descent or Lepcha. The native dialect is mostly Bhutia, Lepcha, or Nepali.
As per the Census of 2011, the hamlet had about 400 families residing with 2495 people. Like many other small villages and towns in Sikkim, Lachung also follows the traditional self-governance system of Dzumsa, where every household in the village is part of the administrative system. Most people in the village follow Hinduism; some belong to the Buddhist community, while few follow Christianity.
Lachung is famous for five different festivals that are hosted here every year. Chaam is a religious festival featuring the dance performance of Lamas. Lossong is celebrated during harvest time in January, which is also the New Year for the Bhutia community. Saga Dawa is another festival important for the Buddhist community marking the birth anniversary of Lord Buddha. Lhabas Dhuchen is a festival celebrated in mid-November to mark the Lord's descent to meet his mother. And, the Drukpa Tse-shi is organized to mark the day when Lord Buddha preached the Four Noble Truths after enlightenment.
All kinds of cuisine are served in this tiny village nestled in the Himalayas – Chinese, North India, South Indian, and more. But, the one cuisine to look out for is the local food. Tourists get to savour the indigenous dishes like thukpa, momos, gundruk and sinki, Kinema, and Phagshapa