| Name of the Candidate | Party Name | Results |
| MADAN MOHAN TIWARI | Indian National Congress | Winner66786 |
| RENU DEVI | Bharatiya Janata Party | 64466 |
| SAMEER HASAN | Independent | 2851 |
| MOHAMMAD SAIDULLAH | Communist Party of India (Marxist) | 1628 |
| LAKSHMI RAM | Bahujan Samaj Party | 1553 |
| PUNYDEO PRASAD | Independent | 1355 |
| RAMESH CHANDRA SINHA | Shivsena | 1348 |
| SHAMBHU PRASAD GUPTA | Samajwadi Party | 1237 |
| POONAM SINGH ALIAS POONAM SINGH PATEL | Independent | 1178 |
| AMAR KUMAR KUSHAWAHA | Independent | 717 |
| ARUN YADAV | Jan Adhikar Party (Loktantrik) | 651 |
| SHRIKANTI DEVI | Rashtriya Jankranti Party | 590 |
| RIZWANULLAH | Janta Dal Rashtravadi | 430 |
| MOHAMMAD FIROJ | Garib Janta Dal (Secular) | 328 |
| ARUN KUMAR SRIVASTAVA | Sarvajan Kalyan Loktantrik Party | 312 |
| KEDAR PRASAD | National Janta Party (Indian) | 215 |
| None of the Above | None of the Above | 1918 |
| AC No | Category | Poll Phases | Last Date of Nominations | Date of Polls | Result |
| 8 | GEN | Phase IV | Oct 7th 2015 | Nov 1st 2015 | Nov 8th 2015 |
Bettiah assembly constituencies is in western Champaran district and is a part of western Champaran parliamentary constituency. It comprises of Bettiah community block; Gram Panchayats- Mohaddipur, Parsa, Bahuarawa, Majhaulia, Gudara, Bakharia, Rulahi, Jaukatia, Rajabhar, Lal Saraiya, Karamawa, Ramnagar Bankat, Majharia Sheikh, Ahawar Kuria, Amawa Majhar, Madhopur, Senuwaria and Bishambharpur of Majhaulia CD Block. A total of 2,20,061 eligible voters are there, out of which 1,18,357 voters are male and 1,01,700 are female.
One of the nine assembly segments located in the Paschim Champaran district of Bihar, Bettiah assembly constituency is currently being represented by Renu Devi who retained the seat as a BJP candidate in the last Bihar assembly polls in 2010 by defeating her nearest rival Anil Kumar Jha by a handsome margin of 28789 votes. While 41829 votes were polled in favour of Renu Devi, Anil Kumar Jha received 13221 votes and was followed by Madan Mohan Tiwari of the Congress who received 12499 votes.
Virval Yadav, who contested on the ticket of the Lok Janashakti Party (LJP), came fourth with 11511 votes. As things stand today, the BJP and the JD (U) have parted ways and LJP is now a part of the NDA, the ruling dispensation at the Centre.
In the November assembly election in 2005 to the Bettiah assembly constituency, Renu Devi emerged victorious from the seat by trouncing Mohammad Shamim Akthar of the Congress by a margin of 16466 votes. In the previous assembly election to the seat held in February that year she had defeated the same opponent by a margin of 11457 votes. Shamim Akthar was in the fray as an Independent.
It has to be borne in mind that Bihar went to the assembly polls twice in 2005 because the earlier one held in February threw hung assembly necessitating the holding of the second assembly polls in the month of November of the same year. In 2000 too, Renu Devi was elected from the constituency.
Earlier in 1995, Virval Yadav had defeated the sitting BJP Bettiah MLA Madan Prasad Jaiswal by a narrow margin of 505 votes. In the previous assembly elections held in 1990, Madan Prasad Jaiswal had defeated independent candidate Nageshwar Shahi by a margin of 6739 votes. Before that Bettiah has been a bastion for the Congress whose candidate Gauri Shanker Pande was elected in 1969, 1977, 1980, and 1985.
Bettiah is one of the six assembly constituencies that combine to form the parliamentary constituency of Paschim Champaran which is currently represented by Sanjay Jaiswal of the BJP who won the seat by defeating his nearest JD(U) Prakash Jha by a margin of 1,10,254 votes in the 2014 Lok Sabha elections. Raghunath Jha of Lalu Prasad's Rashtirya Janata Dal (RJD) was relegated to third place.
BJP has nominated its sitting MLA Renu Devi in Bettiah, an urban constituency in West Champaram district. Renu Devi grabbed 42,010 votes in the 2010 assembly elections to defeat an Independent candidate Anil Kumar Jha who got only 13,221 votes. Madan Mohan Tiwari from Congress is Renu Devi's opponent in Bettiah. Congress candidate expects support from RJD and JD(U) leaders during campaign to beat a strong BJP opposition in the constituency.