Rao breathed his last at a private hospital at Nandigama in Krishna district. He is survived by his wife, two daughters and a son.
The TDP leader was in 2009 elected as the legislator from Nandigama for the first time and won from the seat again in the recently-held elections.
Rao, who was a lawyer by profession, was associated with TDP since its formation.
On Sunday, he had accompanied AP Irrigation minister D Uma Maheswara Rao to the Pulichintala irrigation project to assess the ongoing work.
After his return, he suffered a cardiac arrest late night and was rushed to the hospital where he breathed his last.
Andhra Pradesh Chief minister N Chandrababu Naidu, the Irrigation Minister and other political leaders have expressed grief over his demise.
The funeral will be held this evening at Rao's native Paritala village.