Cobalt substituted Zn–Mn chromites Zn1−xCoxMnCrO4 (0 ≤ x ≤ 1) were prepared by sol–gel method. The synthesized material was characterized by various physico-chemical methods. The temperature of decomposition, crystallization and phase transformation of the as-prepared powder was studied using TGA–DTA measurement. X-ray diffraction patterns revealed that all compositions are in single phase cubic structure. An infra-red spectral study shows two strong bands, which is attributed to the intrinsic vibrations of tetrahedral sites and the octahedral sites. Formation of spherical particles was revealed by scanning electron microscopy analysis. The elemental analysis as obtained from energy dispersive analysis of X-ray is in close agreement with the expected composition from the stoichiometry of reactant solutions used. Magnetic properties were measured by vibrating sample magnetometer. All the compositions indicated ferrimagnetic nature. The substitution of cobalt ions in the lattice affected the structural as well as magnetic properties of spinel.