As to Bachelor's degree, it can be translated with "Diploma di Laurea breve" or simply "Diploma universitario", sometimes called in the press as "Mini-Laurea" (not advisable for a CV). Master's degree is usually a full four-year degree (but 7 years for architecture and medecine) and should be the traditional "Diploma di Laurea).
A PHD is a "Dottorato", it can be "Dottorato di ricerca".

If you visit the site of University of Rome, my alma mater, you will find how those terms are rendered in Italian.
Saluti
Paola Ludovici MacQuarrie

I would agree with incerpi. A Laurea in Italy (in theory, at least) is a 4 or 5-year program of university study ending with a thesis. Many people take much longer, because a student is not forced to take an exam if (s)he does not feel prepared, and so many people put off exams or even refuse grades once they have taken an exam, so that they may be retested with the hope of recieving a better grade. A Masters Degree in Italy is somewhat similar to a Masters Degree in the U.S., but it usually takes less time in Italy,(often 1 year) and usually there is much less writing involved. I hope this helps.