Yes MasterCard works in Italy.
The question really should be does your bank's credit card work in Italy.
Is it a chip & pin card or a chip & sign card (primarily US banks) or a swipe only card?
Having a chip equipped card is essential in Europe as most POS (point of sale) terminals are set up for chip cards not swipe cards.
Does your bank impose any restrictions on overseas use, lower daily limits, etc?
These are questions you need to ask your bank in advance and at the same time notify them where and when you will be traveling so they are aware of potential foreign transactions.
travel.stackexchange.com/users/None/
My recent experience as an American tourist in several European countries, including Italy (Rome and Trieste): MasterCard is widely accepted.
If your card is a "swipe" card (ie, it is neither chip-and-signature nor chip-and PIN), it will work in slightly fewer places, but will still be adequate for your trip.
If your card is a swipe card, read on for some advice and my experience using such a card in Europe: Swipe cards usually work in places with humans running the point of sale, but NOT ticket or other machines, with the important exception of ATMs, where they almost always work.
So, in the context of your question, you could likely make do with a swipe card in all situations except paying for transportation, when it would likely not work.
However, there's a small (maybe 5% in my experience) chance some impossible-to-diagnose error will happen when you try to pay with a swipe card, and you'll be stuck with cash as your only payment option; there's also a larger (10-20%)
chance the cashier or salesperson handling your transaction will be unfamiliar with swipe cards, and you'll have to deal with the point of sale machine yourself, including swiping, possibly entering CVV number, following prompts in a foreign language, etc.
It's a hassle, but it's manageable and easier than opening up a new account if your bank doesn't issue chip cards.
Never rely on a swipe card as your sole method of payment in a critical situation, but make frequent visits to an ATM and you will be fine with a combination of cash and (chip or no-chip) MasterCard.
travel.stackexchange.com/users/36332/Urbana
You Will Need an EMV Supported Credit Card EMV stands for Europay Mastercard and Visa.
This is the new standard for security related to PCI compliance in Europe.
This standard has been adopted in the United States and is currently being rolled out and is behind schedule.
Most large banks support this standard in the US, Europe and most of Asia.
You can goto your bank if you have not already been issued this type of card.
They are frequently referred to as 'chip cards'.
Many banks are increasing their daily withdraw and charge limits if this type of card is being used due to the decreased financial risk to the bank due to the technology.
You will want to discover if there is a delta between a standard card or an EMV card if this is important to you.
travel.stackexchange.com/users/31239/Citizen
I've owned a chip-and-pin MasterCard credit card issued by an Italian bank for several years.
I've used it all around the Italy and in neighbouring European countries.
The only instances in which credit cards might not work, regardless of the payment circuit they use (Visa/MasterCard), is at automatic machines such as the ones found at 24h petrol stations, and some train ticket machines like those found at Malpensa airport.
Swipe-and-signature cards are usually accepted in places where chip-and-pin cards are too.
Indeed the machine will tell you to swipe the card if inserting it in the chip slot doesn't work.
travel.stackexchange.com/users/22140/JoErNanO
You need to ask your bank; as they are the only ones that control where your card works.
It may be true that all MasterCard-network cards work in Italy, and the widest acceptance is that of EMV "chip" enabled cards; but despite this your bank may block the use of the card.
So, before you travel: Inform your bank that you will be traveling to Italy.
Ask them if there are any special instructions regarding your card.
They may have some agreements with banks for lower fees for cash withdrawals; or other restrictions (for example, maximum amount you can withdraw, maximum POS transaction limit, etc) that you may need to be aware of.
travel.stackexchange.com/users/1375/Burhan Khalid
I have a Mastercard and I want to know if they work in Rome or not.  Mainly I want to buy food, pay for entrances, and transportation, and buy gifts and some stuff.
Does MasterCard work in Italy?
travel.stackexchange.com
<italy><payment-cards><rome>
travel.stackexchange.com/questions/61956
travel.stackexchange.com/users/37703/sarah
MasterCard does work in Italy, although the EMV chip-and-pin cards are much more widely accepted. Swipe cards usually work in ATMs and places with humans running the point of sale, but NOT ticket or other machines. Chip and pin Mastercards work in Italy. Swipe Mastercards also work byt there may be some issues, especially in automatic machines. The use of Mastercards in general may be blocked by the issuing bank so it is better to check with them before travelling.
Mastercard with chip and pin works in Italy. There may be issues using a sipe Mastercard in Italy. However, it seems to be useable in some places. Some banks block card use in certain countries, so checking with the bank before travelling is a good idea.