The ruling Congress could bag only three seats, and the All India United Democratic Front (AIUDF) also managed to secure three seats.
Independent candidate Naba Kumar Sarania won the Kokrajhar Lok Sabha seat.
Sarania, a former militant, defeated his rival with the highest margin among all the constituencies.
The BJP won seven out of 14 seats in the northeastern state
Elections to the 14 Lok Sabha seats were held in Assam in three phases April 7, April 12 and April 24. There were 168 candidates in the fray.
The BJP won in Gauhati, Nowgong, Jorhat, Dibrugarh, Lakhimpur, Tezpur and Mangaldai parliamentary constituencies, while the Congress could manage to win only three seats - the Autonomous District (Diphu) constituency, Kaliabor and Silchar.
The All India United Democratic Front (AIUDF), led by perfume baron Moulana Badaruddin Ajmal, also improved its tally this time bagging two more seats compared to the 2009 Lok Sabha polls. While the party retained Dhubri seat, it snatched Karimganj and Barpeta seats from the Congress.
The Kokrajhar seat, which was normally held by the Bodoland Peoples' Front (BPF) led by Hagrama Mohilary, was snatched by Independent candidate Naba Kumar Sarania, who was backed by the non-Bodos living in Bodoland Territorial Areas Districts.
According to the statistics of the election department, the BJP got over 36 percent of votes across the state, while the Congress got 29.5 percent.
The prominent winners among the BJP were the party's Assam unit president Sarbananda Sonowal, who contested against union Minister of State for Tribal Affairs Ranee Narah.
Rameswar Teli of the BJP also sprang a surprise by defeating sitting MP and DONER Minister Paban Singh Ghatowar in Dibrugarh.
BJP's Kamakhya Prasad Tasa won the Jorhat Lok Sabha seat, a known forte of the Congress, from sitting MP Bijoy Krishna Handique of the Congress.
In Guwahati, Mangaldai and Nagaon, the BJP candidates could retain their seats.
The Congress retained its Autonomous District (Diphu) constituency and the Kaliabor seat, Sushmita Deb, daughter of Santosh Mohan Deb, snatched the Silchar seat from BJP's Kabindra Purakayastha.
Assam Chief Minister Tarun Gogoi's son Gourav Gogoi, who is a debutant in politics, won the Kaliabor seat.
AIUDF chief Badaruddin Ajmal retained his Dhubri seat, while his brother Sirajuddin Ajmal also managed to win the Barpeta Lok Sabha seat. Radheshyam Biswas of the AIUDF won the Karimganj seat from Congress' Lalit Mohan Shuklabaidya.
Chief Minister Tarun Gogoi accepted the party's defeat and took full responsibility for the debacle.
"We are going to accept the mandate. I take full responsibility and I am going to tender my resignation to the AICC chairperson," said Gogoi.
BJP president Sarbananda Sonowal said the people of Assam, like the people in other parts of the country, wanted a change this time under the leadership of BJP's prime ministerial candidate Narendra Modi.