The ionic conductivity of two pellets of LiHf2(PO4)(3) calcined at 1000 and 1100 degrees C has been measured. Grain interior and grain boundary responses are distinguished in the impedance plots as well as in the real part of conductivity versus frequency plots. The activation energy associated with the motion of Li+ ions inside the grains is 0.33 eV while the activation energy corresponding to the total d.c. conductivity changes from 0.36 to 0.47 eV, depending on the relative contribution of grain interior and grain boundary to that parameter.