Transfer from Rome airport to Sorrento?

If you are referring to private car service, check out Rome Cabs. It is a private car service -- not a cab company. We can not say enough good things about them as we have used them many times to and from the airport and Rome itself and have always been very pleased. I might be wrong, but I believe they do transfers to Sorrento. Go to romecabs.com and see what you think. We usually send an email and they answer us with a quote within 24 hours. You do have to pay cash (Euros) and the end of the journey but not in advance.

There are many companies to choose from, but I've never used this type of service. Below are just examples:
http://www.transferelax.com/it/noleggio-con-conducente-sorrento.html
http://www.noleggioconducenteroma.com/trasferimento-sorrento-e-positano/

It's a long trip (about 3.5 hours for nearly 200 miles), so as you can see the cost is high (350-450€)

Depending on how many people are traveling together, you may want to consider taking the much faster high speed train from Rome to Naples, then the commuter train (or even a private car transfer) for the last short stretch from Naples to Sorrento.

The full price fare on Standard class on the train from Fiumicino Airport to Naples (change at Roma Termini station) is 58€ per person one way.

The commuter train from Naples to Sorrento is just a few euros, a private car transfer from Naples is about 90€.

If it's only 2 people traveling together, the high speed train Rome to Naples+private car from Naples to Sorrento is a good comfortable choice and it would be half the price.

Cheaper option, but I can't comment on reliability.
http://www.sorrentoshuttle.com/

I have taken train from Rome Termini to Naples then the local to Sorrento. No need to book ahead but to save a few euro. The Naples station is a bit more challenging, watch your belongings, The local to Sorrento can be crowded with several stops depending on the time of travel. but I enjoy the local atmosphere. Just love Sorrento, have fun.
Lorieann

Bought three months in advance, no changes, no refunds, the Frecciarossa train from Rome Termini to Naples can be as little as 29 Euros, AFAIR.

(Referring to another post) There is nothing wrong with the Naples rail station. It is newer and cleaner than virtually all American rail stations. It has the same chance of baggage theft as any American airport or public transportation terminal.

It is true that the Circumvesuviana commuter rail from Naples station (downstairs below ground) to Sorrento is stiflingly crowded and intimidating to fit and watch your luggage on. Nothing bigger than a briefcase will fit in the overhead luggage racks, which you can't reach anyway because they are over the seats, whose aisles are already full of standees!

Fortunately there is an alternative to Circumvesuviana which can be crowded and very hot in summer even in early fall. Take a taxi to Naples harbor and take a boat across Naples Bay to Sorrento. Faster and certainly much more pleasant.

For a private car with a driver, check this out: http://www.fa-dincc.com/index.html I used this company for transport from my hotel to the Rome airport. They also offer private tours.