Raju, who had quit the Bharatiya Janata Party (BJP) to join the Praja Rajyam Party (PRP) floated by superstar Chiranjeevi in 2009, returned to the BJP in the presence of party president Rajnath Singh.
BJP senior leader M. Venkaiah Naidu was also present on the occasion.
Raju, who represented Narsapur Lok Sabha seat in West Godavari district, was minister of state for external affairs in the BJP-led National Democratic Alliance (NDA) government from 2000 to 2004. He, however, lost the 2004 elections from the same constituency.
The actor joined the PRP in 2009 and contested from Rajahmundry Lok Sabha constituency but lost to Congress leader V. Arun Kumar.
After the PRP's disastrous performance in the simultaneous polls to the Andhra Pradesh state assembly and the Lok Sabha, Raju quit the party and was since inactive in politics.
Raju, who turns 74 this month, began his film career in 1966 and has acted in over 180 movies.