A series of polyelectrolyte complexes (PEC) of anionic poly(styrenesulfonate) (PSS) containing Na(+) or Cs(+) as counterions and cationic poly(diallyldimethylammonium chloride) (PDADMAC) were prepared as solid material at monomeric fractions X of PSS ranging from 50 to 75. The dc conductivity was measured as a function of relative humidity by impedance spectroscopy. The water content increases almost linearly with humidity, while the dc conductivity increases exponentially. This general behavior holds for all compositions and both types of cations and it is described by log(sigma(dc)) = a . RH + constant. Comparing different compositions and counterions, we discuss the contributions of different charge carriers and conclude that alkali ions, transported in their hydrated state, are the major conducting species; the contribution from protons is negligible. In addition to properties of the cationic charge carriers, the water content and matrix properties such as the cross-linking density systematically influence the charge carrier mobility.