This is Mr Modi's fourth visit to his home state, where the party is again eyeing a big poll victory, since March.
The prime minister started his roadshow from the Aji dam area and travelled through some of the important landmarks of the city, covering a distance of eight km.
He was seen waving at the huge crowd, which had gathered on both sides of the streets, while the people showered rose petals and threw garlands at him.
Rajkot has a special place in PM Modi's political career. He was elected to the Assembly from the Rajkot-II seat after being appointed the chief minister of Gujarat in 2001. He continued to occupy the post till May 2014, when he became the prime minister and moved to New Delhi.
PM Modi, who is on a two-day Gujarat visit, started the roadshow after welcoming the waters of the Narmada river into the Aji dam, a key source of water for the city.
The BJP has set a target of winning at least 150 of the 182 Assembly seats in Gujarat. Party president Amit Shah has also increased the frequency of his visits to Gujarat, which is his home state as well.