In an interview with Italian gossip magazine Chi, the 72-year-old leader insisted he had never paid for sex.
He alleged a prostitute at the centre of the scandal had been paid to make false accusations against him.
Mr Berlusconi's personal life has been under close public scrutiny since his wife filed for divorce last month.
This is the first time Mr Berlusconi has spoken at length about some of the most serious accusations involving his private life.
An Italian model, Patrizia D'Addario, said last week she had been paid more than $1,000 (£609, 720 euros) to attend a party in his residence in Rome, in the company of other women.
Ms D'Addario alleged she was asked to return and eventually spent the night with the prime minister.
In an interview with Chi, one of Italy's most popular gossip magazines, Mr Berlusconi said he had never paid for sex.
He added: "I never understood where the satisfaction is when you're missing the pleasure of conquest."
And he attacked Ms D'Addario, saying she had been "extremely well paid" by someone to produce false accusations against him.
But she has denied this.
"If Mr Berlusconi has the slightest proof backing his claims he must present them to legal authorities," she told the Ansa news agency.
"If this is not the case, he should not be making such claims."
Under pressure
Mr Berlusconi has been under pressure since his wife, Veronica Lario, filed for divorce after 19 years of marriage, accusing him of improper relations with a young woman.
She criticised her husband for "consorting with minors" and attacked his decision to attend the 18th birthday party of an aspiring TV actress and model.
He has repeatedly denied any wrongdoing.
He faced further scandal when photos were published of topless women and a naked man at his villa on the island of Sardinia.
The prime minister said he could not be blamed for the bad behaviour of others and there was nothing in his private life he should be ashamed of or should apologise for.
Mr Berlusconi has not faced much public indignation in Italy, although the drama surrounding his private life is generating a lot of coverage in those parts of the media he does not control.
Correspondents say many Italians admire Mr Berlusconi for his success - the power, the money and the chance to surround himself with beautiful women if he so chooses.
In recent local and European elections, his Freedom People's party did well, grabbing a few cities from the opposition.
