Modi started his seven-kilometre roadshow by first garlanding the statue of Banaras Hindu University founder Pandit Madan Mohan Malviya.
The prime minister, who was wearing a saffron kurta and scarf, was cheered by a massive crowd as his cavalcade passed through the Lanka and Assi areas of the city.
He is scheduled to perform the ‘Ganga aarti’ at the Dashashwamedh Ghat.
Before reaching Varanasi, Modi had tweeted: “After bumper rallies in Darbhanga and Banda, I am heading to beloved Kashi.”
“There are a series of programmes lined up, which would give me another excellent opportunity to interact with my sisters and brothers of Kashi. Har Har Mahadev!” he had tweeted.
The show of strength takes place on a day the Congress ended all speculation about its general secretary Priyanka Gandhi Vadra taking on Modi in the city.
The Congress has again fielded Ajay Rai from the Varanasi Lok Sabha seat. He had finished third in 2014.
The BJP said JD(U) president and Bihar Chief Minister Nitish Kumar and Shiv Sena chief Uddhav Thackeray will accompany Modi as he files his nomination around 11.30 am on Friday.
Shiromani Akali Dal patriarch and former Punjab chief minister Parkash Singh Badal and Lok Janshakti Party chief Ram Vilas Paswan will also be in attendance, the party said.
On Friday, the prime minister will address booth heads and workers at 9.30 am and then offer his obeisance to Kal Bhairav at 11 am.
“In this (nomination) programme, senior SAD leader and former Punjab CM Parkash Singh Badal, Bihar Chief Minister and JD(U) chief Nitish Kumar, Shiv Sena chief Uddhav Thackeray, central minister and president of the Lok Janshakti Party, Ram Vilas Paswan, will be present,” the party had said in a press release.
Leaders of the AIADMK, the Apna Dal and the North-East Democratic Alliance will also be present, it said.