The mishap took place at Kirthirayunigudem village of Myalavaram Mandal in Krishna district.
K Venkateswara Rao (70) and his grandson K Sudhakar (18) were returning home on a motorcycle when their two- wheeler suddenly skidded, causing both of them to fall, according to Myalavaram Sub-Inspector A Durga Prasad.
Both received severe injures. While Rao died on the spot, his grandson succumbed while undergoing treatment at Mylavaram Government Hospital, he said.
The duo was returning home from Tatigudem village and proceeding towards Gannavaram.