The conducting properties of poly(2-acrylamido-2-methyl-1-propanesulfonic acid) solutions in protic and aprotic solvents have been studied. Aprotic solvents such as dimethylformamide, mixtures of dimethylformamide and propylene carbonate, dimethylacetamide, as well as protic solvents such as water, methanol, glycerol and oxyethylene glycols were used. Colorless solutions or flexible membranes with ambient conductivity in the range of 1-10(-6) S cm(-1) were obtained depending on the kind of solvent used and polymer concentration. The effect of parameters connected with the mobility and concentration of protons, such as electrolyte viscosity, type and composition of solvent as well as the share of the polymeric matrix on the conductivity of the electrolytes studied has been discussed on the basis of the results obtained. (C) 2003 Elsevier Science Ltd. All rights reserved.