Lawngtlai is located in the southern panhandle of Mizoram. The district shares international borders with Bangladesh to the west and Myanmar to the east, as well as domestic borders with Lunglei and Saiha districts. The geography of the town and surrounding region is defined by highly rugged, mountainous terrain, deep gorges, and narrow river valleys.
The region is characterized by a tropical and subtropical environment, boasting rich biodiversity. It is surrounded by dense evergreen and deciduous forests that are home to varied flora and fauna. Major rivers like the Chhimtuipui (Kaladan) flow through the district, carving through the landscape and serving as a vital natural resource for the region.