Vatican and St Peter's Basilica or in reverse?
 

What are the queues like for St Peter's in the morning? I am thinking of going there first and doing the Vatican after lunch. We were in Rome 4 years ago in the early morning with a snake long queue around the Vatican. After a rather hurried private tour of the Vatican crushed by tourists all over the place and a short stop at St Peter's we had lunch outside. After lunch, we saw that there was no longer a queue to enter Vatican. I am guessing that the mob is still inside at this time but at least you no longer have to wait a long time to get inside or like us be forced to book a private tour - running after a private guide who is in a rush and whom we could barely hear due to the crowds. I am no longer booking a tour this time around as I will be travelling with my kids. I've seen that Context Rome does a 3hr tour catered to kids but 3hrs would be really stretching it as far as my kids are concerned. I figure just go inside and see a few things - mainly the Sistine Chapel.

Alternatively, I am considering visiting them separately. I am a Catholic and would really be interested in attending one of the masses - particularly the one on Sundays that proceeds the Vespers at the Altar of the Chair. Would the queues to get in the Basilica still be long on Sundays when the Vatican Museum is closed? Would St. Peter's be even be more crowded around this time? Also, can we access the grottoes from the basilica since it is under the basilica or is it part of the museum? And would this be open on a Sunday.

The queues to the Basilica move quickly. Unless you're there on a special holiday I don't think you should be concerned about the wait.

By Vatican, I assume you mean Vatican Museums. I don't have a lot of experience there, but it's commonly reported here on Fodors that afternoons are generally much shorter or non-existent lines. You can go directly from the Sistine Chapel into St. Peter's, thereby avoiding waiting in line again.

There are 2 exits to the Sistine Chapel - I believe the one at the back labeled groups is the one that will take you to St. Peters.

<<< I believe the one at the back labeled groups is the one that will take you to St. Peters >>>

Indeed it is and it's just supposed to be for groups - but no-one stops you using it and saves a long walk. Just ensure that yu've done the rest of the Vatican first

I'd head to the Vatican Museums first, at mid-day when the crowds have lessened. Even if you head directly to the Sistine Chapel, your children will get a good taste of the museums opulence, passing the tapestry hall, the map gallery, lots of sculptures and paintings along the way. You could divert to the Raphael rooms just before the Sistine Chapel if you like.

Then leave by the group entrance on the right (don't check bags at the museum entrance if you plan to do this) and you will have skipped the long walk back to the museum entrance, the long walk around the walls as well as the security line to St Peter's, arriving in a courtyard to the side of the basilica, right next to the line for the dome climb.

I did this route in late November with friends and we were leaving by the group exit after about 90 minutes.

alanRow is correct. We just got back from there a couple of months ago. Rick Steves has many tips on skipping that outrageous line for the Vatican. Get a reservation. They will tell you to go stand in the line but when your reservation time is approaching, brazenly walk to the front, show the man gaurding the roped off entrance and show him your reservation and inform him your time is right now. He will lift the rope and let you thru. Inside the Vatican, we had a little snack before making our way thru the museum. After seeing the Sistine, facing the back wall there is an exit to the left and one to the right. Take the one on your right and it will dump you into the courtyard area to go into St. Peters. There is a short line, but if you leave that area and try to come back, you will have to wait in line to get in the line to get into St. Peters. Rick Steves has TONS of tips to help with lines. The only line we've ever waited at was at Versailles in Paris because of his books.

I did the same thing, more or less, that ellenem suggested. I arrived at the Vatican Museum entrance around 1pm, walked right up, bought my ticket and went in. On that day, at least, there was no line whatsoever. I have a large travel "purse", really a tote bag, but didn't check it. I toured the museums and Raphael Rooms at my leisure, finally making my way to the Sistine Chapel. Having been there before, I knew about the "group exit" door and used it, walking directly to St. Peter's.