Dielectric and conductivity spectra of the compound Li 1−x Ni 1+x O 2 (x = 0.03) are reported and analysed. The spectra were recorded for compacted powders within the broad frequency range 10-10 10 Hz at temperatures varying between 210 and 300 K. The evolution of the spectra of the sample with respect to the damage under air allows us to define two regimes: the first one is an interfacial regime and the second a bulk regime. The frequency of crossover (ν co ) between the two regimes lies in the interval 1 × 10 9 and 2 × 10 9 Hz at room temperature. At frequencies below ν co , the spectral analysis shows dielectric relaxations due to interfacial polarization phenomena in the sample. The complex resistivity plots (for ν < ν co ) allowed the determination of the dc conductivity of Li 1−x Ni 1+x O 2 versus temperature. At frequencies greater than ν co , one dielectric relaxation corresponding to small-polaron hopping has been observed. The corresponding relaxation frequency is thermally activated with an activation energy of 0.15-0.16 eV and a pre-exponential factor ν 0 ≈ 3×10 12 -4 × 10 12 Hz, which is of the order of the longitudinal-optical-phonon frequency ν L O . The conduction behaviour is interpreted in terms of hopping of small polarons (holes) on an oxygen network.