The conductivity of nominal CaWO4, CaW0.99Ta0.01O4-, 0.7(CaWO4)-0.3(La0.99Ca0.01NbO4-), and Ca0.9La0.1WO4+ has been studied by means of a.c. impedance measurements. Proton conductivity was observed for CaW0.99Ta0.01O4-, which displayed exothermic hydration with enthalpy and entropy of -82 kJ/mol and -120J/molK, respectively. The proton mobility in CaW0.99Ta0.01O4- was low, with enthalpy and preexponential factor of mobility of 82kJ/mol and 0.7cm(2)K/Vs. The high enthalpy of mobility is interpreted to reflect association between the acceptor dopant and protonic defects, whereas the low preexponential factor of mobility may reflect a lower proton concentration than assumed. Rietveld refinement indicated low solubilities of La on Ca-site and Ta on W-site. Proton conductivity was also observed in undoped CaWO4, however, not in Ca0.9La0.1WO4+. The conductivity of 0.7(CaWO4)-0.3(La0.99Ca0.01NbO4-) behaved much like that of undoped LaNbO4, likely due to a very low acceptor dopant concentration.