Bihar Exit Polls: What Was Predicted In 2015 And 2020, And How Accurate They Turned Out — Here's A Look
Exit polls are often seen as a precursor to the final results. But, how accurate were they in the last two assembly elections of Bihar? Here's a look.

Bihar is a state seen tricky for pollsters, as the electoral sentiment is weighed upon by an array of factors, including caste arithmetic, law and order, and development plank.
In the last two assembly elections, the exit polls failed to project an accurate picture of the final outcome. In 2015, the pollsters underestimated the victory of the Mahagathbandhan, whereas in 2020, they went totally wrong in predicting the National Democratic Alliance's (NDA) loss.
Similar to the last assembly polls, the Bihar assembly polls 2025 also largely witnessed a two-sided contest, pitting the Bharatiya Janata Party and Janata Dal (United)-led NDA against the Rashtriya Janata Dal (RJD)-Congress-headed Mahagathbandhan.
Here's a look at what the 2020 exit polls had projected, and how the final results emerged:
An average of 11 exit polls projected the Mahagathbandhan as the winner, bagging around 125 out of the total 243 seats. On the other hand, the NDA was shown to be winning around 108 seats — 16 less than the halfway majority-mark.
On the day of results, however, the NDA managed to retain power, winning 125 seats, whereas the Mahagathbandhan fell short of wresting the state, as it could win only 110 constituencies.
What happened in 2015?
Back then, the Mahagathbandhan also comprised of the JD(U); whereas the NDA was headed by the BJP, and included smaller regional players. An aggregate of six major exit polls had projected a tight race, giving the Mahagathbandhan a slight edge. The coalition was projected to win 123 seats, whereas the BJP-led alliance was expected to be restricted to 114.
Three exit polls predicted an outright Mahagathbandhan win, two projected an NDA triumph and one showed a hung verdict.
However, on the day of results, the Mahagathbandhan defied the pollsters by forming the government with a two-third majority. The coalition won 178 seats, whereas the NDA could win just 58 constituencies. Two years later in 2017, however, the Nitish Kumar-led JD(U) severed ties with the Mahagathbandhan and re-aligned with the BJP, thereby leading to the return of the NDA government.
