"The BJP is heading for an absolute majority and Modi will be the next PM," Naidu told a press conference.
Naidu said Bihar and Uttar Pradesh, which together account for 120 Lok Sabha seats, will account for the lion's share of the BJP strength in parliament.
"The BJP is set to perform well, and more than expected in Bihar and UP."
He added: "We don't believe in forward and backward castes but it is true that Modi will be first PM from a backward class."
Naidu said Modi stood for "3 Ds -- decision-taker, dynamic and development-oriented".
He said Modi will end the dynastic rule of the Gandhi family.