The complex oxide LiFeTiO4 was prepared by an usual solid state method and its crystal structure has been refined by Rietveld's analysis of powder X-ray diffraction data. These results indicate a spinel-type structure in which all titanium cations are in octahedral sites whereas lithium and iron cations are distributed on tetrahedral and octahedral sites, nearly in the same ratio, that could be expressed by the formula : (Li0.47Fe0.53)[Li0.53Fe0.47Ti]O-4. The ionic conductivity measured on polycrystalline samples has been obtained by ac techniques in the temperature range of 473-873 K.