Cubic-structured NiO, Co 3 O 4 and spinel-structured NiCo 2 O 4 were synthesized via microwave route. The structural properties of NiO, Co 3 O 4 and NiCo 2 O 4 nanostructures were investigated by X-ray diffraction analysis, and it showed smaller crystallite size for NiO than Co 3 O 4 and NiCo 2 O 4 by using Williamson–Hall method. Flake-like and hexagonal plate-like morphologies were ascertained from HRSEM and TEM analyses. Optical properties of these materials were investigated by photoluminescence study, and it presents the band edge emission for all materials with supplementary emissions in visible region due to the presence of defects such as vacancy and interstitial. Raman and FTIR spectra provide the functional characteristics of NiO, Co 3 O 4 and NiCo 2 O 4 nanostructures. XPS measurement revealed the purity and composition of these nanostructures. Room temperature magnetic measurements were investigated using vibrating sample magnetometer. The low coercivity and remanent magnetization for NiO, Co 3 O 4 and NiCo 2 O 4 nanostructures confirmed that these nanoparticles exhibit a weak ferromagnetic behaviour.