The electrical conductivity of some γ-irradiated and unirradiated metal-zinc ferrites, M0.1Zn0.9Fe2O4 (M ≡ Mn2+, Co2+, Ni2+, Cu2+ or Mg2+), was investigated as a function of temperature. The ferrites investigated showed n-type conduction. The electrical conduction in M0.1Zn0.9Fe2O4 (M ≡ Co2+, Cu2+, Mn2+, or Ni2+, can be explained by a hopping mechanism, whereas the conduction in ZnFe2O4 and Mg0.1Zn0.9Fe2O4 is interpreted on the basis of the transfer of charge carriers through the cation vacancies present in octahedral sites. The effect of γ-irradiation on the conduction process is discussed.