What the results mean for national politics:
Prime Minister Narendra Modi's ability to swing state elections has been reinforced in a key state that has 40 Lok Sabha seats, of which the BJP won 39 in last year's national election.
The BJP is now stronger in Bihar even without a strong leadership in the state. In Bihar, its senior most leader is Sushil Kumar Modi, who shares a good rapport with Nitish Kumar.
With Bihar, the BJP has ended a dry phase in which it suffered a series of state losses to different coalitions. An example was Maharashtra, where an unlikely partnership between its former partner Shiv Sena and the NCP and Congress stopped the BJP coming to power.
The results in bypolls held across a dozen states also favoured the BJP, which is seen as a measure of PM Modi's winnability.
While Mr Tejashwi failed to turn the huge crowds attending his rallies into a landslide, the 31-year-old established himself as a key state leader in his own right. He managed to push Nitish Kumar's party to third place. But giving the Congress 70 seats to contest may have been his biggest miscalculation.
The Congress this time contested more seats than in 2015 but ended up with only 25 per cent of them. That has prompted its critics to once again label it a liability for its allies with few leaders to match PM Modi's appeal and vote-winning ways.
Congress's only star campaigner was Rahul Gandhi, none of the other Gandhis - his mother Sonia and sister Priyanka Gandhi Vadra - travelled to Bihar.