The fast ionic conductor Li2AlZr[PO4](3) has been prepared by the solid state reaction method. The formation of the compound is confirmed by XRD and FTIR analysis. The system has been subjected to ac conductivity measurements in the temperature range 523 to 623 K with aluminium as blocking electrodes over a frequency range of 42 Hz to 5 MHz. The conductivity is found to be 1 x 10(-5) S cm(-1) at 623 K. The activation energy calculated from the Arrhenius plot is 0.83 eV. The conductance spectrum reveals a d.c. plateau and a dispersive region that suggest the correlated hopping motion of ions. Thus, the conduction mechanism in Li2AlZr[PO4](3) may be due to the hopping of charge carriers. (c) 2005 Elsevier B.V All rights reserved.