Chouhan, 54, was administered the oath of office and secrecy by Madhya Pradesh Governor Ram Naresh Yadav at a ceremony held at Jamboree ground here, shortly after noon.
The entire BJP top brass, including its prime ministerial candidate Narendra Modi, party chief Rajnath Singh, veteran L K Advani and senior leaders of its allies Shiv Sena and Shiromani Akali Dal attended the swearing in ceremony, amid tight security arrangements.
Known for maintaining a low-profile, Chouhan led the BJP to win an impressive 165 seats in 230-member legislative assembly reducing Congress tally to just 58 from 71 in 2008.
Banners, posters, flags and pamphlets carrying Chouhan pictures were put alongside roads, markets and the venue.
The oath-taking ceremony was attended by Leader of Opposition in Lok Sabha Sushma Swaraj, Leader of Opposition in Rajya Sabha Arun Jaitley and Chhattisgarh Chief Minister Raman Singh, among others.
Rajasthan Chief Minister Vasundhara Raje Scindia, Goa Chief Minister Manohar Parriker and Punjab Chief Minister Parkash Singh Badal also attended the function.
Former Andhra Pradesh chief minister and Telugu Desam Party president Chandrababu Naidu, who is of late cozying up to the saffron party, was also present along with industrialist Anil Ambani.
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