It can be difficult to change money other than euros and US dollars, even currency from neighboring countries! You might find more flexible exchange offices at airports, but be prepared for service fees and poor exchange rates. USD bills smaller than $100 can also be hard to break without accepting a lesser exchange rate.
The national currency is the Boliviano. As of January 2010, the exchange rate is generally Bs6.97/$USD or Bs10/EUR. Bills come in denominations of 200, 100, 50, 20, and 10; coins are in 5, 2, and 1 Bolivianos, and 50, 20, and you will find sometimes 10 centavos 1/10 of a Boliviano. Bills larger than Bs50 can be hard to break, but a quick phone call or internet session at an Internet CafÃ© see Contact, below will usually get you change.
Currency can be exchanged for US dollars and most South American currencies at Casa De Cambio agencies or street vendors. Expect to negotiate for a favorable exchange rate, as most vendors will try to make money off a tourist.
U.S. dollars are widely accepted in hotels, tourist shops, and for large purchases.
Banco de Credito is a good bank to take cash from. Banco Union should be avoided if possible as it charges a 5% surcharge as of May 2012, although they do not make any mention of this.