Suitably selected ionic liquids (ILs) are first applied as antistatic agents for poly(methyl methacrylate) (PMMA) and poly(butyl methacrylate) (PBMA) films in this study. We have compared volume-and surface-resistivity (Rv and Rs) on the basis of the morphology of the composite films. These values were found to deeply relate to the compatibility. For pure polymer films, both Rv and Rs were found to be around 10(12) Omega cm and 10(14) Omega cm(-2), respectively at 60 degrees C. These values were reduced hundred times by adding 10 wt% of the ILs having a high compatibility with polymer matrices. When the compatibility is good enough, ILs are uniformly incorporated into the matrices, and accordingly the films are properly plasticized and fully transparent. We also show that the incorporation of ILs, having poor compatibility with polymethacrylates, results in the turbid films with a concomitant reduction of Rs but not of Rv, attributed to the bleed out of the ILs from the films. We believe that assuring the transparency of the film and suppressing undesired washing out effect of ILs are major tasks, and hence, we conclude that ILs showing high affinity with polymethacrylates are the most promising antistatic agents for polymethacrylates. (C) 2017 Elsevier Ltd. All rights reserved.