Assam Chief Minister Sarbananda Sonowal, Meghalaya Chief Minister Conrad K Sangma, Nagaland Chief Minister Neiphiu Rio, his deputy Y Patton, Tripura Chief Minister Biplab Deb and Manipur Chief Minister N Biren Singh along with BJP general secretary Ram Madhav were among others who attended the swearing-in ceremony.
Six sitting cabinet ministers, including Chowna Mein, Wangki Lowang, Honchun Ngandam, Kamlung Mossang, Alo Libang and Bamang Felix, have been included in the new ministry.
Deputy speaker Tumke Bagra and two sitting MLAs Mama Natung and Tage Taki also found berth in the cabinet.
Two newcomers -- Taba Tedir and Nakap Nalo -- were also inducted in the new ministry with cabinet rank.
Khandu, talking to reporters after the swearing-in ceremony, thanked the people of the state on behalf of Prime Minister Narendra Modi and party president Amit Shah for voting the BJP to power in the Himalayan state.
"It is a historic day for the state as the BJP could install a government on its own," Khandu said and asserted that his government would be clean, transparent and corruption-free.
The chief minister announced that the priority areas would be improvement in law and order, health and education sectors.
"Our government will explore every possible avenue to provide employment opportunities to the unemployed youths and will invite outside investors to invest in state's potential sectors for gainful employment of local youths," Khandu said.
Khandu along with his cabinet colleagues will go to New Delhi to attend Modi's swearing in as the prime minister for the second consecutive term.
The BJP led by Khandu won 41 seats in the 60-member House, in the assembly polls held simultaneously with the Lok Sabha election on April 11 in the northeastern state bordering China.
While the opposition Congress could win only four seats, the Janata Dal United in its maiden entry in the state's political scene won seven seats.
Another new entrant National People's Party (NPP) bagged five seats.
While one seat went to the lone regional outfit of the state People's Party of Arunachal (PPA), two seats were won by Independents.