A facile and cost-effective sol–gel technique has been used to synthesize nickel chromite (NiCr2O4) nanoparticles (NCNPs) at 700°C to investigate their photocatalytic together with antibacterial and anticancer activities. The synthesized nanopowder was characterized by Thermogravimetric thermal analysis (TG-DTA), X-ray Diffraction Spectroscopy (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), High-Resolution Transmission Electron Microscopy (HR-TEM), Fourier Transform-Infrared Spectroscopy (FT-IR), X-ray Photon Electroscopy (XPS) and UV–Visible Diffuse Reflectance Spectroscopy (UV-DRS) and Photoluminescence (PL). Beyond 700°C, the thermal durability of NCNPs was confirmed by TG-DTA analysis. The synthesized NPs were cubic structured corresponding to their spinel structure, a crystallite size of 38[Formula: see text]nm and an optical bandgap of 2.7[Formula: see text]eV. The PL spectra revealed emission bands in the visible and UV regions. The surface-phase-pure elemental and electronic arrangement of the NCNPs were verified by X-ray photon spectroscopy. Photocatalytic activity of NCNPs against Methylene Blue dye revealed 89% degradation in 1[Formula: see text]h. The in vitro antibacterial and anticancer activities of NCNPs were also examined. Among the tested microbes, Staphylococcus aureus exhibited the highest level of sensitivity (9[Formula: see text]mm), while Escherichia coli had the lowest (5[Formula: see text]mm) against NCNPs. The MTT test revealed the significant cytotoxicity of NCNPs against carcinogenic HeLa and MCF-7 cells. Thus, the synthesized NCNPs could be rated as potential photocatalytic, bactericidal and anticarcinogenic agents.