A spokesman said the billionaire businessman-turned-politician would not step down.
"Berlusconi, the government and the majority will continue to govern," Berlusconi spokesman Paolo Bonaiuti said, calling the ruling "a political verdict."
The Constitutional Court's 15 judges overturned the law that caused the suspension of a trial in which Berlusconi was charged with ordering the 1997 payment of at least $600,000 (euro408,329.93) to British lawyer David Mills in exchange for the lawyer's false testimony at two hearings in other corruption cases in to the 1990s.
The 2008 law was passed by Berlusconi's conservatives while the premier was on trial in Milan.
Berlusconi denied the corruption charges, and his lawyers have argued in court on Tuesday that he could not be a defendant and at the same time serve as premier.