Most ‘skip the lines’ tours are indeed legitimate.
The lines outside the Vatican can be horrendous – more than an hour long during popular months – and all those people are waiting to buy a ticket.
Guided tour companies buy tickets in bulk in advance, so with them you will be able to walk straight past the lines with your guide.
However, you don’t have to go on a guided tour to skip the lines: you can skip them yourself by buying Vatican tickets online. If you do this, make sure to print out your online ticket voucher (you may need to use the hotel’s business center) and bring it with you, because they will need to read the bar-code on the voucher.
Once you have your voucher, walk right past the huge line outside to the right-hand side of the main Vatican door and show your voucher to the guys in front. They’ll let you through the security scanner and then you need to go to one of the counters on the left in order to get your online voucher validated and turned into a ticket, which you then use at the turnstile at the top of the first set of escalators.
Having said that, there is a lot to be said for having a guide. Though relatively expensive, they add a significant and important layer of comprehension and interpretation to your trip, and also can direct you to the key pieces in the museum. The museum has 8 miles of corridors and it’s easy to wander for hours without finding what you want!
Another advantage of going on a guided tour is that it also allows you to skip the lines at St Peter’s Basilica, since there is a corridor exclusively for tour groups that goes directly from the Sistine Chapel into the basilica.
Our tip is to book in advance online with a reputable guide company such as Walks of Italy or Dark Rome (though Dark Rome tends to have huge groups, which can feel very impersonal). They tend to have high standards and to constantly vet their guides’ standard of English. The TripAdvisor ‘things to do in Rome‘ page can give you a rough idea of the quality of different companies.
What we wouldn’t recommend doing is waiting until the last minute and buying a place on a tour from the many hustlers in the streets surrounding the Vatican, as you really can’t tell what kind of tour guide you might be getting – they could be good, they could be terrible, or the experience might be a scam.
However you decided to go there, the Vatican Museums are worth the effort or the wait, and the ceiling of the Sistine Chapel – the crowning achievement of mankind’s genius – is worth braving the crowds for.