Baksa district was carved out of a part of Nalbari, Barpeta, Kamrup and small portion of Darrang district. As a result of historic BTC(Bodoland Territorial Council) accord signed on February 10, 2003, formed BTAD(Bodoland Territorial Autonomous District) with four districts namely Kokrajhar, Chirang, Baksa and Udalguri. Though the original word 'Baksa' is not above controversy, a good chunk of population prefer to use 'Bagsa' in lieu of 'Baksa'. The popular assumption that 'Baksa' is the misspelt form of 'Bangsa'--a 'Dzonkha' word meaning a farm house and a corridor as it is known that Bhutanese king and subjects used this area for trade and passage to the plains. 'Bangsa' (Bagsa or Baksa) was in fact one of the most important 'Dooars' of Bhutan.

Another source says that the name "Bagsa" is originated from Bhutanese language. According to Bhutanese origin they denoted the area as "Bagsa Duar". "Bagsa" meaning one kind of rice and "Duar" meaning entrance point. As Bhutanese king ruled these areas for a long time in an around first half of the nineteenth century so it might be possible that the name "Bagsa" or "Baksa" had a Bhutanese origin.

According to Bodo source the name originated from a kind of rice grain which is known as "Bagsa". The said rice grain is one kind of broken and uncleaned product which is gained after milling the rice.

As the name Baksa is itself derived from various sources and antecedents so there exists lots of controversy over the name. But still today no concrete evidence has been found which might determine the final source. Only popular sources and folklores are evident but no historical source has been found. So serious research needs to be done in this respect.

Now the name Baksa is officially taken and used.
1. Geographical area 2400 Sq. Km (Approx)
2. Population 9.53773 Lakhs      (as per 2011 census)
3. Sub-Divisions Mushalpur (Sadar), Tamulpur(Civil), Salbari(Civil)
4. No. of Revenue Circles 6
5. No. of Dev. Blocks 8
6. Total Police Stations 8
7. Total Out Posts 11
8. Total Patrol Posts 5
9. No. of Villages 687
10. No. of Tea Gardens 4
11. No. of BTC Constituencies 11
12. No. of LAC(major part) 3