Some participants identifying themselves as Roman Catholics in this overwhelmingly Catholic country, said Qaddafi had urged others to convert to Islam and had dismissed Christianity as unimportant.
Michela, who asked that her last name not be used, told Associated Press Television News that three of the participants converted to Islam on the spot Sunday.
"It was a really beautiful meeting and went very well," she said. "He is very easygoing and he gave us a copy of the Quran. Three girls converted themselves to Islam during the ceremony. It was a beautiful event."
It was the second time the Libyan leader -- who travels with female bodyguards and fancies himself a self-styled feminist -- had staged such an event for Italian women, who were recruited by a modeling agency and paid an undisclosed sum to attend.
Between 200 and 500 young women attended, arriving 10 buses at the Libyan ambassador's residence just as Gadhafi's plane was landing at Rome's Ciampino airport at the start of a two-day visit.
The visit, amid steadily improving business ties between Libya and its former colonial ruler, also marks the second anniversary of a friendship treaty in which Italy agreed to pay Libya $5 billion as compensation for its 30-year occupation, which ended in 1943.
When Qaddafi was in Italy in November for a U.N. food summit, he hosted 200 young Italian women who had been recruited and paid about $75 by the same modeling agency to attend. Then, too, he gave a lecture on Islam and handed out copies of the Koran.
This time around, the women wouldn't say how much they had been paid, only that they had received a small "reimbursement."
During his first visit to Italy in June, 2009, Gadhafi invited 700 prominent Italian businesswomen and female politicians to listen to a lecture in which he criticized Islam's treatment of women but also suggested male relatives should decide if a woman can drive.
As part of the friendship treaty anniversary celebrations, some 30 Libyan horses were arriving in Rome to take part in a joint demonstration with Italy's carabinieri equestrian forces on Monday, news reports said.
Qaddafi made his first visit to Italy in June, proclaiming a new era in relations following the friendship treaty. But that first visit also was marked by a symbolic demonstration that the wounds of colonialism still ran deep: He arrived wearing a black-and-white photo pinned to his military uniform of a Libyan national hero killed by Italian colonial authorities.
Qaddafi sported no such photo upon arrival Sunday at Ciampino, where he was greeted by Foreign Minister Franco Frattini.
Despite the colonial past, Italy and Libya have long had good ties, and major Italian corporations such as oil giant Eni have invested heavily in the oil-and-gas rich country.
Libya's central bank, meanwhile, has a 4 percent share in Italy's largest bank UniCredit, which earlier this month won the first international license to operate in the North African country.