This study examines the short- and long-run effects of changes in macroeconomic variables—agricultural commodity prices, interest rates and exchange rates—on the U.S. farm income. For this purpose, we adopt an autoregressive distributed lag (ARDL) approach to cointegration with quarterly data for 1989–2008. Results show that the exchange rate plays a crucial role in determining the long-ran behavior of U.S. farm income, but has little effect in the short-run. We also find that the commodity price and interest rate have been significant determinants of U.S. farm income in both the short- and long-run over the past two decades.