The spreading of ionic liquids on molecularly smooth solid surfaces has been little studied in the past. We show that the spreading behaviors of the two ionic liquids, [EMIM] ethyl sulfate and ECOENG (TM) 500, are well described by the combined molecular kinetic and hydrodynamic model of de Ruijter, de Coninck, and Oshanin [M.J. de Ruijter, J. de Coninck, G. Oshanin, Langmuir 15 (1999) 2209] with reasonable values for the molecular friction coefficient zeta, molecular displacement lambda, and frequency K-0 associated with contact line motion, as well as reasonable values for the microscopic cutoff a associated with hydrodynamic dissipation. (C) 2009 Elsevier Inc. All rights reserved.