Cobalt oxide based nanostructures are perspective materials for gas sensors, photocatalysts, and other devices for ecology applications due to the high concentration of chemisorbed oxygen and catalytic activity in oxidation reactions. Finely dispersed nanocrystalline oxides Zn_xCo_3−xO₄ (0 ≤ x ≤ 1) with a high level of conductivity have been synthesized by the chemical precipitation of oxalates with subsequent thermal treatment. Comprehensive studies of the morphology, electrophysical properties, nature and concentration of defects in the obtained materials were carried out. It is shown that the introduction of zinc atoms to the Co₃O₄ structure leads to a sharp increase in conductivity by more than 5 orders of magnitude. In addition, the zinc-induced interplay of Co²⁺ spin centers between tetrahedral and octahedral sites was revealed using the EPR method. The correlation between the conductivity and the concentration of Co²⁺ ions in tetrahedral and octahedral environments was established for the first time. The obtained results open up the possibility of fine-tuning the electronic properties of nanostructured Zn_xCo_3−xO₄ by variation of zinc concentration in the samples.