1. Early in the morning, between 7:00-8:00 a.m., you may usually join the Masses celebrated by Priests individually or in small groups (see above for the days allowed). Just ask the guards where the sacristy is, and as you see the Priests going out of the sacristy, ask them in what language they will celebrate, and if you may attend.
2. Later in the day, unless there is a Papal celebration, Masses are regularly celebrated by different priests, mostly in Italian or Latin, almost every hour in the morning, and one Mass towards 5:00 p.m. Click here for Mass schedules at St. Peter’s and other Major Basilicas.
3. Priests may celebrate Mass at St. Peter’s Basilica with a group (but not individually by himself) by making a reservation at this link, indicating the requesting party’s and the celebrant’s name and contacts, as well as the number of Priests and lay faithful and the language for the Mass (bring your own Missal and readings if celebrating in non-major European languages). In the space for the note, you may request the use of special Altars in the Crypt such as the Altare della Confessione di San Pietro (small groups only), or those of Pope John Paul II, Pope John XXIII, etc
a) Masses may start at 7:15 or 8:15 am. on any day except on Wednesdays when the Holy Father gives an Audience outdoors on St. Peter’s Square, and on other days with celebrations at St. Peter’s Basilica or St. Peter’s Square (go to the Vatican website and click on Calendar to check).
b) On the scheduled day, Priests should bring their celebret. The Sacristy will provide the liturgical vestments, vessels, linens, and liturgical books in the language you requested. Concelebrant priests, if four or more, should kindly bring their own alb and stole.
c) Loud singing is not allowed, since chapels are near each other.
d) A simple renewal of vows with an exchange of rings may be done after the homily (but without bringing in flowers, candles, cords, veils, etc.) using a prepared text (find and replace names, modify first and third lines, and modify third page information). Make sure the anniversary they are celebrating is their Church wedding, by asking in what parish they were wed, and who the officiating Priest was, if they remember.
e) For further questions, call +39 06 6988 1496.