Commodity exports depend on global demand and prices, but the increasing volatility of real exchange rates (RER) introduces an additional factor. Thus, this paper studies the RER volatility dynamics, estimated through GARCH and IGARCH models for Brazil, Chile, New Zealand, and Uruguay from 1990 to 2013. We study the impact of RER volatility on total exports using Johansen's methodology, including proxies for global demand and international prices. The results suggest that exports depend positively on global demand and international prices for all countries; however, conditional RER volatility resulted significant and negative only for Uruguay, in the short-and long-run.