I actually have dual citizenship in Italy and the US, so it's allowed between the two countries, but I was born there (parents both US citizens). Not sure about what you're asking, but why would you want to, out of curiosity?
Also, be mindful of the age of whoever is asking. There is a military commitment up to a certain age there. Until I was over 26, when I went to visit, I had to bring certain paperwork or else I would have been immediately drafted for 2 years when I got off the plane. I was only allowed to stay for 3 months at a time, as well.