| Name of the Candidate | Party Name | Results |
| DR. RAMANUJ PRASAD | Rashtriya Janata Dal | Won 86082 |
| VINAY KUMAR SINGH | Bharatiya Janata Party | 49686 |
| BINOD KUMAR SINGH | Independent | 3606 |
| PRADEEP KUMAR SAHNI | Sarvajan Kalyan Loktantrik Party | 3265 |
| SUDHIR KUMAR SINGH ALIAS BHOLA SINGH | Independent | 2312 |
| ASHOK SINGH | Independent | 2172 |
| HEM NARAYAN SINGH | Shivsena | 1394 |
| SUKHNNANDAN SINGH RATHOR | Communist Party of India | 1142 |
| AMOD KUMAR SINGH | Samras Samaj Party | 891 |
| RAJKUMAR HAZRA | Independent | 712 |
| GONAR MAHTO | Independent | 539 |
| SITA SAROJANI | Samajwadi Party | 443 |
| KUMAR SAMARJEET SINGH | Jawan Kisan Morcha | 350 |
| None of the Above | None of the Above | 4290 |
| AC No | Category | Poll Phases | Last Date of Nominations | Date of Polls | Result |
| 122 | GEN | Phase III | Oct 1st 2015 | Oct 28th 2015 | Nov 8th 2015 |
Sonepur legislative assembly segment is in Saran district and a part of Lok Sabha Constituency. It is is home to 2,56,197 eligible voters, out of whom 1,38,084 are male and 1,18,109 are female. Sonepur legislative assembly segment consists of Dighwara and Sonepur community development blocks.
Once represented by former Bihar Chief ministers Ram Sundar Das and Lalu Prasad, Sonepur in the Saran district of Bihar is currenly held by Vinay Kumar Singh of the BJP who hogged the limelight when he won the seat in the last general assembly elections to the state in 2010 by defeating Lalu Prasad’s wife and former Bihar Chief Minister Rabri Devi by a handsome of 20685 votes in a straight contest.
In that election to Sonepur, while Vinay Kumar Singh received 64676 votes, Rabri Devi, who became the Bihar Chief Minister when Lalu got entangled in the infamous fodder scam, secured 43991 votes and was distantly followed by the Congress candidate Ajay Singh who obtained just 2884 votes. In 2010, Rabri Devi had lost the Raghopur assembly seat in Vaishali to Satish Kumar of the Janata Dal (United). Vinay Kumar Singh had earlier also claimed the Sonepur seat in 2000 when he trounced Ramanuj Prasad of the Lalu led Rashtirya Janata Dal (RJD) who however went to defeat the former in both the elections in 2005.
While Lalu Prasad had emerged victorious from the Sonepur seat in 1980 and 1985 on the tickets of Charan Singh led Janata party (secular) and Lok Dal respectively, Ram Sunder Das was elected in 1977 as a Janata Party candidate. Ram Sunder Das failed to retain the Hajipur Lok Sabha seat on the ticket of the JD(U) in 2014 due to the Modi wave sweeping Bihar at that time and was relegated to the third place. In 2014 he lost to Ramvilas Paswan , the Lok Janashakti Party supremo who in turn was defeated by him in the previous parliamentary elections in 2009.
Sonepur is one of the six assembly constituencies that combine to form the parliamentary constituency of Saran which is currently represented by BJP Union minister Rajiv Pratap Rudy who won the seat in the 2014 Lok Sabha elections by trouncing former Bihar Chief Minister Rabri Devi by a margin of 40,948 votes. While Rudy polled 355120 votes, Saleem Perwez of the JD (U) was relegated to the third place with 107008 votes.
Other five assembly constituencies that are parts of the Saran parliamentary seat are Parsa, Chapra, Marhaura, Garkha and Amnour.
It will be an interesting contest between Vinay Kumar Singh from BJP and Ramanuj Prasad from RJD in Sonepur.
Sonepur is known for the largest cattle fair where thousands of bovines are transported to the central market here for display and purchase.
The issue of cow slaugther is a very sensitive issue in Sonepur.
RJD chief Lalu Prasad Yadav's remark that Hindus too eat beef has created an uproar.
In a counter, state BJP leader S.K.Modi assures that his party will ban cow slaugther if it is voted to power.
It may be noted that thousands of animals used to be brought to Sonepur fair by trains from across the country and transported to Assam and other North-East states.
From the NE states, the cattle are being transported across the border for slaughter, which Sushil Modi said, he had banned when he was a minister.