This work aims at developing and characterizing a proton conducting polymer electrolyte based on Poly(N-vinyl pyrrolidone) (PVP) doped with ammonium bromide (NH4Br). Proton conducting polymer electrolytes based on PVP doped NH4Br in different molar ratios have been prepared by solution casting technique using distilled water as solvent. The XRD pattern confirms the dissociation of salt. The FTIR analysis confirms the complex formation between the polymer and the salt. The conductivity analysis shows that the polymer electrolyte with 25 mol % NH4Br has the highest conductivity equal to 1.06 x 10(-3) S cm(-1) at room temperature. Also it has been observed that the activation energy evaluated from the Arrhenius plot is low (0.50 eV) for 25 mol % NH4Br doped polymer electrolyte. The influence of salt concentration on dc conductivity and activation energy of the polymer electrolyte has been discussed. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 127: 1538-1543, 2013