Barahathwa is a municipality of Sarlahi District in Janakpur Zone of central Nepal. The municipality was established on 18 September 2015 by merging the existing Barahathwa, Murtiya, Hajariya and Laukat village development committees (VDCs). The center of the municipality is establish in former VDC Office of Barahathwa Bazaar. After merging the four VDCs population it had a total population of 50,424 according to 2011 Nepal census. After the government decision the number of municipalities has reached 217 in Nepal.