Leoluca Bagarella, a former mafia top dog arrested in 1995 and sentenced to several life sentences for a spate of murders, received the heaviest sentence — 28 years although the prosecution had called for only sixteen.
Ex-police chiefs Mario Mori and Antonio Subranni were both slapped with 12-year sentences along with former-senator of Silvio Berlusconi's Forza Italia party and a close ally of the ex-premier, Marcello Dell'Utri.
Dell'Utri is already serving a seven-year sentence for collusion with the Mafia.
Former mafia boss Antonino Cina, was also sentenced to 12 years behind bars.
The verdict is only the first ruling in the trial and likely to be subject to a lengthy appeal process.
The trial, which began in 2013 in Palermo, thrust the spotlight on alleged negotiations between government officials and mafia bosses following a series of bomb attacks and assassinations in the 1990s.
Prosecutors allege that after the assassinations of two top anti-mafia judges in 1992, senior Italian officials engaged in secret talks with the mafia.
The accusation is that they agreed to be lenient, allowing for fewer trials and easier prison conditions, in exchange for an end to the attacks.
Minister of the Interior at the time, Nicola Mancino was acquitted of the charge of false testimony.
Over the course of the trial, former Italian President Giorgio Napolitano was also summoned to give evidence, a first for a serving head of the Italian state.
“This is a historic verdict,” said magistrate Nino Di Matteo, one of the prosecution's representatives.