The counting of votes began on 10 November 2020 and the incumbent National Democratic Alliance emerged as the winner with 125 elected MLAs, whereas the principal opposition coalition of Mahagathbandhan won 110 seats.

However, in 2017, the Janata Dal (United) Chief Minister Nitish Kumar left the Mahagathbandhan and joined the National Democratic Alliance.

Bihar, for a long time, has been an economically backward state and sends large numbers of migrant laborers to cities across the country.

[8] The three agriculture bills passed by the Indian Parliament amid nationwide protests was expected to play a key role in the elections.

[9] Issues such as the lack of employment, alleged politicisation of flood relief in the aftermath of the 2019 Bihar floods and alleged inability of the state government to handle the COVID-19 pandemic were expected to be made an election issue by the opposition parties.

[10][11] The limited digital connectivity in Bihar and the migrant crisis were among the issues which may have had an impact on campaigning and poll outcomes.

[13] It was reported that the BJP accorded special focus on the politically significant Mithila region which comprises 22 of the 38 districts of the state including Darbhanga, Madhubani, Supaul, Araria, Purnia, Katihar and Samastipur.

[24] In 2018, two of the partners, the Rashtriya Lok Samata Party and the Hindustani Awam Morcha left the alliance.

[25][26] During the campaigning phase in August 2020, the alliance was re-joined by the Hindustani Awam Morcha which held one seat in the legislature.

[28] The campaign however faced problems with persistent attacks on the Janata Dal (United) by the Lok Janshakti Party.

[43] The Bharatiya Janata Party at the time re-asserted that Nitish Kumar would remain the chief ministerial face of the alliance.

[44][45] Both the Lok Janshakti Party and the Janata Dal (United) are expected to hold sway among certain sections of Scheduled caste voters while the Bharatiya Janta Party are expected to draws its support base from Forward caste voters.

[46][47] The Janata Dal (United) though relied upon its core voters by giving importance to its Luv-Kush equation in ticket distribution, also gave good representation to the forward castes and EBCs.

[62] The seat sharing agreement was finalised on 3 October 2020 with the Jharkhand Mukti Morcha included in the alliance.

[64] In the wake of the 2020 Bihar Legislative Assembly election, Upendra Kushwaha pulled the party out of the Rashtriya Janata Dal led Mahagathbandhan (Grand Alliance).

[69] There were a number of other smaller parties and coalitions contesting the election,[71] the prospects and impact of these formations have been noted to be marginal.

[105] On 27 October 2020 a day before the first phase of the election, three improvised explosive devices (IEDs) were recovered and diffused from two different places in Imamganj area of Gaya district.

[111] Rashtriya Janata Dal won in 75 constituencies and became the largest political party in the Legislative Assembly, however its numbers reduced compared to previous election.

[113][114] The Janata Dal (United) and Indian National Congress won in 43 and 19 constituencies respectively and dropped the most seats compared to the previous election.

[123] In districts adjoining Uttar Pradesh, the BJP performed better than the Mahagathbandhan, however JDU's seats declined.

After the election process concluded, Chief Minister Nitish Kumar tendered his resignation to the Governor on 13 November 2020.

[126] The National Democratic Alliance members met at around 12:30 pm IST, on 15 November to formally announce and elect the new Chief Minister.

[130] After the election results were announced, the incumbent Chief Minister of Bihar Nitish Kumar thanked the Prime Minister of India Narendra Modi for his contribution and support to the National Democratic Alliance in the election campaign.

He claimed, that the MGB "lost about 20 seats" because of "irregularities" in counting of postal ballots[134] and threatened to move to court.

[140] The Time magazine called the victory as a triumph for Modi's "Hindu Nationalist Message".

[143] 2021 bye-election was necessitated by the death of sitting MLAs of Kusheshwar Asthan and Tarapur assembly constituencies.