Neutron reflectometry measurements suggest that the interfacial structure normal to the free surface of two short-chain amphiphilic 1-alkyl-3-methylimidazolium-based ionic liquids is inhomogeneous, with the inhomogeneity extending similar to40 Angstrom. For the two liquids studied (1-butyl-3-methylimidazolium tetrafluoroborate and 1-octyl-3-methylimidazolium hexafluorophosphate), the data are consistent with a stratified surface model with distinct regions of alkyl chains and ionic headgroups.