Modi, who was present at the oath-taking ceremony in Shimla, took to Twitter to congratulate chief minister Jai Ram Thakur and his council of ministers.
"Congratulations to Jairam Thakur and all those who took oath today. I am confident this team will work tirelessly and serve the people of Himachal Pradesh with exceptional diligence," he tweeted.
Meanwhile, in Shimla, Modi also "relished coffee at the Indian Coffee House".
The BJP had won 44 out of 68 seats in the state assembly and after the shocking defeat of BJP's chief minister face Prem Kumar Dhumal from Sujanpur, the race was open for the top post and Jai Ram Thakur was elected leader.
Besides Modi, Union ministers Rajnath Singh, Nitin Gadkari and J P Nadda along with chief ministers of BJP-ruled states such as Yogi Adityanath, Manohar Lal Khattar, Devendra Fadanvis and Sarbanand Sonowal were present on the occasion.