Getting Married in the Vatican
Many Catholics are interested in being married at St. Peter's Basilica. If your priest lives in Rome, he can make the arrangements for you. Couples need to begin the process no more than six months and no less than four months before the intended wedding date. If you are interested in getting married in Rome (outside the Vatican City), please visit the American Embassy to Italy website at http://italy.usembassy.gov/acs/marriage/general-marriage.html for information about requirements and other consular-related issues.
The Santa Susanna website is a very helpful tool for those who wish to get married in the Vatican.