Raju, who had been a minister in the NDA government, joined BJP in the presence of its President Rajnath Singh here.
Raju, who hails from coastal Andhra, had joined Chiranjeevi's erstwhile Praja Rajyam after quitting BJP.
Meanwhile, Singh had a meeting with the office-bearers of state unit of BJP and discussed the preparations for Lok Sabha and Andhra Pradesh assembly elections, party sources said.