After hearing final arguments from the prosecution and the defence this week, judges at Italy's top court retired to consider their decision which is expected from 1500 GMT, court officials said.
The panel of judges has to decide whether or not to uphold a temporary ban from parliament and one year of community service or house arrest for the scandal-tainted billionaire tycoon.
They could also send the case back to appeal.
Security was beefed up in Rome outside the courtroom and Berlusconi's residence, with several riot police vans seen parked nearby.
There have been reports of possible protests planned by both pro- and anti-Berlusconi activists, whichever way the ruling goes.
Even if Berlusconi's conviction is upheld, however, the sentence cannot be implemented until the Senate votes to lift his parliamentary immunity - a process that could take weeks or even months.
The case revolves around Berlusconi's business empire Mediaset - the starting point for his first foray into politics in the early 1990s.
His tumultuous career has been constantly dogged by legal troubles which he says are politically motivated attacks by left-wing prosecutors.
The current trial is Berlusconi's second and final appeal in the case, which first went to trial in 2006.
If he loses, it would be his first definitive conviction since all past rulings against him have either been overturned on appeal or the charges have expired due to Italy's slow justice system.
He is also appealing convictions in other cases for having sex with an underage prostitute, abusing his prime ministerial powers and leaking a police wiretap to damage a political rival.
Prosecutors have also filed charges alleging he bribed a senator to join his ranks in a move that helped bring down the government in 2008.
"I haven't slept for a month. I wake up at night and stare at the ceiling, thinking about what they've done to me," the media magnate said in an interview with Libero newspaper on Sunday.
"I will not go into exile. Nor will I accept being entrusted to social services, like a criminal who has to be reeducated," he said.
Former prime minister Bettino Craxi, one of Berlusconi's mentors, fled to Tunisia in the early 1990s after being put under investigation and was convicted of corruption in absentia.
But Berlusconi sounded bullish about his chances.
"I am quite optimistic, they cannot find me guilty. I was the prime minister (at the time of the alleged crime), what could I possibly have known about contracts for television rights?"
The 76-year-old Berlusconi has repeatedly been written off and bounced back in the past.
After being dramatically ousted from power in 2011 in a blaze of sex scandals and financial panic, he re-emerged with a powerful election campaign this year that won him a third of the vote.
Analysts said there was a possibility the supreme court could decide on a compromise ruling that would uphold part of the conviction and send the rest of the case back to the appeal courts.
Any new trial would likely see the charges expire before it can conclude as the statute of limitations for the case kicks in next year.
Stefano Folli, a columnist for the Il Sole 24 Ore business daily, said this solution would limit the fallout for Prime Minister Enrico Letta's coalition between the centre-right and the centre-left.
Berlusconi has said there should be no effect on the government even if he is convicted but diehard supporters are threatening to resign from parliament - a move that could trigger fresh elections.
The government was installed this year following a two-month deadlock between Berlusconi's coalition and a leftist grouping led by the Democratic Party after February elections in which the two came neck-and-neck.