We report a preliminary study on novel protonic membranes, obtained by the gelification of a selected polymer matrix in a highly stable ionic liquid solvent, i.e., 1,2-dimethyl-3-n-propylimidazolium bis(trifluoromethylsulfonyl)imide (DMPI-Im). The addition of an acid, chemically compatible with the ionic liquid thanks to the equality between the anionic components, gives rise to a reasonably high conductivity which, together with the good mechanical and thermal stability as well as an excellent control on the methanol crossover rate, make the membranes of interest for practical applications. © 2005 The Electrochemical Society. All rights reserved.