ATMs at Rome Airport

I would expand that to ATMs on the outside of the bank it belongs in case you have problems with the machine.

The ones with bank names on them.

Stay away, if possible, from the ATMs with the names of currency exchange companies on them (like Travelex) as those usually don't give good rates.

Ya, the ones with bank's name on them is a bank owned ATM. If in doubt, don't use it. I just find it easier to carry a hundred euro in and worry about the ATM the following day.

Keeping some euro from the last trip gets me through the start of my next trip in the eurozone.

If you can, get 50-100 euros before you leave. Fiumicino's ATMS ("bancomat") sometimes are out of order. I often wonder if that's to drive you to use the exchange services, which charge ridiculous fees. I could just be paranoid...

But bank ATMs: Unicredit is almost everywhere. Look for that, it's a red and white logo. Also if you see a logo that looks like a weird "3," that's a bank ATM.

The Bancomat machines I’ve seen at FCO were from Unicredit,Italy’s largest bank.

My view is to take that advice with a grain of salt. I would agree that the larger the organization that operates the ATM, the less likelihood you will encounter a problem, but even that chance is remote. I have avoided the small sketchy looking ATMs set out in a convenience store, but regularly use ATMs in airports and stand alone in town, with no issue. Some things to keep in mind....

• "conversion rates" are not an issue, all ATM networks use the same conversion rate, but Dynamic Currency Conversion (DCC) is a concern. DCC is where the institution operating the ATM (or Credit card terminal) offers to do the conversion for you rather than allowing the network to do it, basically they report the transaction in "Dollars" rather than euros. The problem is that they change at a rate much worse than the network. Plenty of big banks do this, you will run into it when using a credit card as well as an ATM, you will always have the option to do the transaction in the local currency, do that, avoid transactions in Dollars or your "home currency".
• Fees added on by the ATM operator are an issue as well, they are less common in Europe, but seem to be popping up more and more. Again, a fee will be noted and an option to cancel the transaction, do so and find another ATM.
• The assumption that if you use an ATM in a bank or attached to a bank during banking hours is "safer" or if you have a problem they can resolve it is just that, an assumption. If your card for instance does not work...there likely is nothing they can do. If the machine were to eat your card or fail to dispense cash, again, likely little they can do other than give you a phone number to call. The bigger the bank, then likely the less anyone in the branch can do as ATMs are usually handled by a separate group or subcontracted all together.

In the end, avoid DCC, use a Bank Branded ATM if that makes choosing easy...though it need not be at a branch, pick an ATM based on convenience and when you need cash.

Contrary to what Paul said, privately owned ATM’s do not use the same exchange rate as bank owned. The smaller, conveniently located non-bank machines at FCO charge around 5% more even without DCC. Just look forUni-Credit.

I guess that would be a new wrinkle, but in decades of ATM use and using a wide variety of ATMs, I have never run into a case where the exchange rate was anything other than the Interbank rate plus a small fixed fee and a percentage of transaction totaling just under 1% that is built into the transaction by the major Networks (Star, Plus, a few others) For the ATM operator, the only options are to add a Fee for use, and/or do DCC. They are obligated to disclose both...though how they do it is up to them. Some just ask if you would like to do the transaction in local or home currency (or some question to that effect) others will "quote" a rate... "200 euro will cost you $241, would you like to proceed?". If you are on the ball, you can see that $241 is about 5% higher than the current rate of $1.17 per euro, but the end game is the same, they are doing DCC.