This study examines the effect of global factors on domestic monetary policy reaction functions of five West African Monetary Zone (WAMZ) countries for the period 1980–2015.The generalized method of moment approach was used for the estimation on the policy reaction function. The study provides strong evidence that global inflation and output gap influenced monetary policy decisions of Central Bankers in the countries of WAMZ. Therefore, it is recommended that global variables should not be ignored and be given appropriate weight while forecasting domestic inflation and making monetary policy rules.