Out of that number less than ten are Italian citizens, Rai News reported.
Earlier this year it was reported that an Italian woman, who converted to Islamic, was among the jihadists.
Addressing the Schengen Committee, Mario Papa said that while the number was small, the main problem is dealing with their potential return to Italy.
Italy's cabinet last month approved a slew of anti-terrorism measures, including jail terms of up to six years for "foreign fighters" as well as those who recruit would-be jihadists.
The measures, put together after the deadly shootings by Islamic extremists in Paris in early January, also included confiscating the passports of suspected militants and giving more powers to Italy’s intelligence services.
Over 3,000 Europeans have joined Isis, more than half coming from France, Rai said.
French officials on Wednesday claimed that a young boy and man who appeared in an Isis execution video are French citizens.
The man is believed to be a relative of Toulouse gunman Mohamed Merah, who killed seven people in 2012.