After the seven-year-long trial, Additional Senior Civil Judge Venkataramana sentenced Maoist leader Panduranga Reddy alias Sagar and three traders of gelatine sticks - Ramaswamy Reddy, Nagarjuna and Gangi Reddy.
The court, which examined 96 witnesses including Naidu, also imposed a fine of Rs.5,000 on each of the accused.
Naidu, then chief minister, his ministerial colleague B. Gopalakrishna Reddy and two legislators were injured as the Maoists triggered a mine blast at Alipiri when they were on their way to the famous Hindu temple to make offerings on Oct 1, 2003.
The attack was meticulously planned by the Maoists, but the TDP chief survived with minor injuries.
Though the prosecution named 33 people as accused in the case, only four could be arrested. Some of the accused including top Maoist leader and prime accused Patel Sudhakar Reddy were killed in alleged gun battles with police while others remain at large.
Sudhakar Reddy, believed to be the mastermind behind the attack on Naidu, was killed by police in a gun battle in Warangal district last year.
