Rosera is one of the 243 constituencies in Bihar, which went into poll in the first phase of assembly election. Bharatiya Janata Party, Indian National Congress, Bahujan Samaj Party, and Jan Suraaj Party are fighting to capture power in Rosera. This seat is reserved for the scheduled cast.
The sitting Member of Legislative Assembly is Birendra Kumar. He is associated with BJP. Kumar won the seat from Nagendra Kumar Pawan of Congress in 2020 assembly election with 87,163 votes and a margin of 16.47%.
Paswan secured 51,419 votes in the previous election. Krishna Raj from Lok Janshakti Party, Vijay Kumar Ram from BSP, and independent candidates — Shrawan Kumar, and Surendra Das were other runner ups in the election.
The total voter turnout in the seat was 55.08% in Rosera in 2020 Assembly election.
In Bihar 2025 election, BJP's Kumar joined the fight again for the MLA office in Rosera. Amit Kumar Baitha from BSP, Braj Kishore Ravi from Congress, Devendra Kumar Paswan from Bhartiya Mahasangh Party, Rohit Kumar from Jan Suraaj Party are engaged in the battle.
Rosera was incorporated as an assembly constituency in 1952 and since then it had been part of 18 general assembly elections till now. For last two decades, Rosera has been an intense battle field between Congress and BJP, which shows that the area mirrors natiotnal politics.
Rosera is part of the Samastipur Lok Sabha constituency.