What is the currency in Argentina?

The currency of Argentina is the Peso. US Dollars are also accepted in some hotels and for many tourist-related services. 

Although most major currencies can be exchanged in Argentina, the US Dollar gets the best exchange rate and is the easiest to change locally. Exchange facilities are available at airports, banks, and bureaux de changes (Cambios) in all larger towns and cities. It's advisable to request bank notes in smaller denominations, as it can sometimes be hard to get change from large notes and smaller notes are handy for smaller purchases and gratuities.

Most major credit and debit cards are accepted in Argentina and ATMs can be found in larger towns and cities, although be aware that the maximum amount that can be withdrawn is often low. Do not rely on credit or debit cards as your only source of money. In some small towns, you may find you’ll need to use cash so the combination of cash and cards is best.

Traveler's Cheques are not recommended as they're often difficult to exchange and incur high fees.