| Name of the Candidate | Party Name | Results |
| VIJAY KUMAR CHOUDHARY | Janata Dal (United) | Won 81055 |
| RANJEET NIRGUNI | Bharatiya Janata Party | 47011 |
| LALAN KUMAR ISHWAR | Jharkhand Mukti Morcha | 3565 |
| RABINDAR PARSAD RAY | Independent | 3051 |
| RAM VILAS ROY VIMAL | Communist Party of India | 2262 |
| BRAJKISHOR SINGH CHAUHAN | Communist Party of India (Marxist-Leninist) (Liberation) | 1814 |
| NANDKISHOR SAH | Loktantrik Sarvjan Samaj Party | 1492 |
| SAJAN KUMAR MISHRA | Samajwadi Party | 1487 |
| RANJAN KUMAR THAKUR | Bahujan Mukti Party | 1258 |
| RAJ NARAYAN SAHNI | Bahujan Samaj Party | 788 |
| MANI DEVI | Shivsena | 652 |
| PARMANAND PATEL | Garib Janta Dal (Secular) | 544 |
| None of the Above | None of the Above | 7294 |
| AC No | Category | Poll Phases | Last Date of Nominations | Date of Polls | Result |
| 136 | GEN | Phase I | Sep 23rd 2015 | Oct 12th 2015 | Nov 8th 2015 |
Sarairanjan is a legislative assembly constituency is a part of the Ujiarpur Lok Sabha constituency. The Sarairanjan assembly segment consists of Vidyapati Nagar and Sarairanjan community development blocks. The Sarairanjan constituency accommodates a total of 2,35,258 voters of whom 1,25,377 male and 1,09,881 female voters in the constituency.
One of the ten assembly constituencies located in the Samastipur district of Bihar, Sarairanjan was won by Vijay Kumar Chaudhary of the Janata Dal (United) in the last assembly polls to Bihar in 2010. In that election, Vijay Kumar Chaudhary, currenlt a minister in the Nitish Kumar cabinet, had polled 53946 votes to defeat Ramashraya Sahni of the Rashtriya Janata Dal (RJD) by a margin 17557 votes. Ramashraya Sahni, a former RJD MLA, received 36389 votes and was followed by Abhash Kumar Jha of the Congress who secured 8652 votes.
Vijay Kumar Chaudhary, son of former Dalsinghsarai MLA Jagdish Prasad Choudhary, was defeated in the October/November elections in 2005 by Ram Chandra Singh Nishad who had emerged successful also in the 2005 February polls. Ram Chandra Singh Nishad had won both the elections in 2005 on the ticket of the RJD. Vijay Kumar Chaudhary had emerged winner from the Dalsinghsarai assembly seat in 1985 and 1990 as a Congress nominee.
Earlier Ramashraya Sahni had claimed the Sarairanjan assembly seat in 2000 as a nomine of the RJD by defeating Chandra Kant Chaudhary of the BJP. Ramashraya Sahni had also won the seat in the previous assembly elections in 1995 on the ticket of the Janata Dal.
In 2010 the BJP had won 91 seats whereas the JD (U) managed to claim 115 seats, becoming the single largest party. While the RJD put up a dismal performance with only 22 seats, the Congress was able to win only four.
Sarairanjan is one of the six assembly constituencies that combine to form the parliamentary constituency of Ujiarpur which is currently represented by Nityanand Rai of the BJP who won the seat in the 2014 Lok Sabha elections by defeating his nearest RJD rival Alok Kumar Mehta by a margin of 60,469 votes.
Other five assembly constituencies that are parts of the Ujiarpur parliamentary seat are Morwa, Bibhutipur, Patepur, Ujiarpur and Mohiuddinnagar.
The BJP candidate Ranjeet Nirguni here has vowed not to get married until he wins the assembly seat. However, he will face a tough contest in Sarairanjan in Samastipur district from his Mahagathbandhan challenger Vijay Kumar Chaudhury.All the 10 constituencies in Samastipur will witness a keen tussle between the BJP-led NDA and the grand alliance floated by the ruling JD(U) and its partner RJD.