Ionic liquids (ILs) have attracted large amount of interest due to their unique properties. Large effort has been focused on the investigation of their potential application, characterization of ILs properties and structure-property relationships. In this paper a simple equation has been used to prediction the surface tensions of pure ionic liquids based on enthalpy of vaporization. Acentric factor, critical temperature, and critical pressure of ionic liquids are necessary inputs for this prediction. The average relative error obtained from the comparison of experimental and calculated surface tension values for studied ionic liquids are less than 2%. Therefore, the model has good accuracy in comparison with other predictive equations. (C) 2013 Elsevier B.V. All rights reserved.