He breathed his last at a private hospital at the early hours, family sources said. He is survived by three daughters and a son.
Rao was a member of the undivided Andhra Pradesh assembly for five times from Karimnagar district.
He actively participated in the Quit India Movement and in the armed struggle against the Nizam of Hyderabad. He had gone underground along with other leaders while fighting the Nizam’s army.
A former member of central council of the Communist Party of India (CPI), he was first elected to the Andhra Pradesh assembly in 1976 from Sircilla constituency. He was re-elected from the same constituency in 1978, 1985 and 1994.
After his long association with the Communist movement spanning over five decades, Rao joined the Telugu Desam Party (TDP) in 1999 but lost the election from Sircilla. He, however, was elected on TDP ticket in the 2004 election.
When the movement for a separate Telangana state intensified, he joined the Telangana Rashtra Samithi (TRS) but later retired from active politics.
His son Chennamaneni Ramesh is a member of the Telangana assembly.
Maharashtra governor Chennamaneni Vidyasagar Rao and economist Chennamaneni Hanumantha Rao are the brothers of Rajeswara Rao.
Telangana Chief Minister K. Chandrasekhar Rao, his Andhra Pradesh counterpart N. Chandrababu Naidu and leaders of various political parties have condoled the death of Rajeswara Rao.