Ben Ali, who has been in Saudi Arabia since he was forced from power six months ago, was found guilty of theft and unlawful possession of cash and jewellery.
Judge Touhami Hafian, who read out the verdict and sentence in the Palace of Justice in the Tunisian capital, said the verdict on other charges, relating to illegal possession of drugs and weapons, would be pronounced on 30 June.
More serious charges, including plotting against the security of the state and murder, will be dealt with at future trials.
During the hearing, a prosecutor had asked the judge to hand down “the most severe punishments for those who betrayed the trust and stole the money of the people for their personal gain. They did not stop stealing for 23 years”.
In a statement issued by his lawyers earlier on Monday, Ben Ali denied all the charges against him, saying that he was the victim of a political plot. He also said he had been tricked into leaving the country.
“I devoted my life to my country and aspire, at the twilight of my existence, to conserve my honour,” Ben Ali said.
He claims he was persuaded to get on a plane that was taking his wife and children to safety in Jeddah, but had the intention of returning immediately.
Ben Ali, the first leader toppled during the Arab Spring, now faces a long legal process that involves 93 charges against him and his inner circle. 35 charges will be referred to a military court.
The Tunisian government has requested for Ben Ali to be extradited from Saudi Arabia, but it is reported it has not received a response.