Polypyrrole (PPy) was doped with the azocalix[4]arene [(5,11,17,23-tetrakis[(p-carboxyphenyl)azo]25, 26,27,28-tetrahydroxycalix[4]arene)] host species. PPy/azocalix[4]arene salts were characterized by FTIR, TGA, SEM, X-ray diffraction, and conductivity measurements. The properties of PPy were investigated in the presence of azocalix[4]arene host species. The conductivity of PPy increased in the presence of azocalix[4]arene. TGA results indicated that the PPy/azocalix[4]arene salts have higher thermal stability than PPy. It was observed from SEM analysis that the particle diameter of PPy decreased with increasing content of azocalix[4]arene. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 2697-2702, 2010