Resorts in the Dominican do accept Pesos (the local curerency) and the American Dollar is accepted at most resorts. Other currencies are not readily accepted or changeable at the resorts.  A lot of guests find out they cannot exchange their country currency at the hotel or they are charged a high rate of exchange and have to make arrangements to do so at a local money store or bank.  Many travellers get local currency from  ATM machines. People do tend to get a better deal with goods when they use Dominican Pesos with the local vendors. Away from the resort areas the U.S. Dollar is NOT widely accepted and if it is a poor rate of exchange is to be expected. Tolls and Gas Stations around the country require Pesos only.

Also, be aware that  most ATM machines have a 10,000 Peso per transaction limit up to your own Bank's daily limit. Also be advised that all ATM's (except Scotia Bank) now charge an ATM fee of 120 Pesos per transaction plus your own Bank's fees. Be sure to check the currency exchange rates for the time you are in the country so you know exactly how much you are paying for goods and services.  A good place to check daily exchange rates is on any currency exchange page on the internet. ATM's in the Dominican Republic only dispense Pesos.