Demand for money is an important part of the macroeconomic models and the monetary policy. In this paper, we estimate the Iranian demand for money for the period 1958-2003using the Autoregressive Distributed Lag (ARDL) method. The results show that the real money balance, gross domestic product, inflation, foreign exchange rate, and government budget deficit have been co-integrated with each other. We also use the error correction model for short-run dynamic analysis. The result shows the speed of adjustment toward the long-run balance is slow.