Padovese's driver Murat Altun stabbed the 63-year-old bishop to death in June 2010 "for uncertain reasons," the court said, ruling out that the killing was premeditated.
Altun was last month convicted of fatally stabbing Padovese at his home in the southern Turkish province of Hatay. Padovese, who died in hospital soon after the attack, was bishop of a diocese in the town of Iskenderun near the city of Antioch.
Altun had given several conflicting accounts of what happened, including that Padovese had molested him and that he had wanted to "kill the demon".
The court said it was possible that Padovese had tried to convert Altun to Christianity. Reports at the time of the murder cited police as saying Altun suffered from clinical depression.
The killing was the latest in a string of attacks in recent years on Christians in predominantly Muslim Turkey, where Christians make up less than one per cent of the population of 70 million
In 2006, Catholic priest Andrea Santoro was murdered in the Black Sea town of Trabzon in an attack blamed on ultra-nationalists and a year later another priest, Adriano Franchini, was stabbed and wounded in the stomach in the western city of Izmir.
The same year, a group of men entered a Bible-publishing house in the central Anatolian city of Malatya and killed three Christians, including a German national.