The state of Mizoram, India, constitutes of eight districts, out of which Kolasib District is one. The northern portion of Mizoram contains the district of Kolasib. The district shares its border on the north with the district of Cachar and Hailakandi District, on the northwest by the state of Assam and with Aizawl District of Mizoram on south and east, while the district is surrounded by the Mamit District on the south west.

Location wise, a much significant position is occupied by the district of Kolasib, since from Mizorams other regions this place forms a principal form of road links. Along the north south direction of the district, the National Highway No. 54 stretches through the districts center. Bairabi located in the state of Mizoram, contains the sole Rail Base of the state. Vairengte, located in Mizoram state contains the solitary base for Military Counter Insurgency & Jungle Warfare School of India. In Asia and also in the entire world, this centre for Military Counter Insurgency & Jungle Warfare School is the biggest as well as renowned. The district shares its border with the district of Assam named Hailakandi District on the north and northwest direction, with Assams Cachar District on the northeast and with Aizawl District of Mizoram on south and east, while the district is surrounded by the Mamit District on the west. The administrative headquarters of the district is located in the district of Kolasib.