When you travel to a new country, one of the most important things you need to consider is the safety. The major concern here is the risk of carrying cash. In Yerevan majority of cafes, restaurants, shops accept credit and debit cards; however, you will need cash more. There are ATMs available all around Yerevan, in other big cities you can also find several, but if you are going somewhere less populated you will need cash. Public transportation, taxis, open markets and many other places do not accept credit cards (if you are taking a taxi make sure that you have some change).
Yerevan is safe, and you don’t have to worry if you are carrying a useful amount of cash. Avoid empty streets at night, don’t count your money outside and be attentive if you use public transportation (there are some pickpockets, but not many).
If you didn’t manage to get local currency in advance, you could always find exchange points in Yerevan (avoid exchanging money in the airport). All the banks have exchange points, where they accept US and Canadian dollars, Euro, Russian Ruble, Georgian lari, British pound, etc. If you want to exchange not commonly spread currency, you can always do it at the Central Bank of Armenia. In case you want to exchange big amount of money you might be asked to present your ID or passport.
In the RA sales are carried out only in Armenian drams (AMD).