We just came back from Chile, Argentina, and Uruguay. As stated, dollars are accepted everywhere. You can use any major credit cards for large purchases. Please be advised that the U.S. dollar has lost its value and expect higher prices. For example, the cost of entering Chile has gone up from $100 to $131. Imagine the surprised faces of Americans holding $100 bills and then being told it has gone up to $131. Perhaps the most amusing example are the craft markets/vendors...they are charging more and are less likely to haggle...but it was all fun.