ZnGa2O4:Cr3+-persistent phosphor is synthesized using different synthesis techniques involving solid-state, sol–gel, and co-precipitation methods. The photoluminescence (PL) was measured using the visible range excitation with 429 nm which reveals some fine peaks which further analyzed with the help of CC model. There is a discernible difference in emission peak intensity when the synthesis route is altered, with the most pronounced emission intensity by the solid-state method. The average crystallite size is highest for solid-state synthesized sample and shows good crystallinity in comparison to sol–gel and co-precipitation synthesized samples. The morphology of the samples also got altered on alteration of synthesis approach in which it was observed that particles are more agglomerated in sol–gel and co-precipitation synthesized material. Energy-dispersive X-ray spectroscopy (EDS) confirms the formation of desired stoichiometry and elemental composition having no organic impurities. The radiative decay curves corresponding to solid-state synthesized sample is observed. The average phosphorescent lifetime is found to be 5.3 ms. The ZnGa2O4:Cr3+ is non-toxic and have a wide range of application in sensors, light emitting diodes (LEDs), and anti-counterfeiting techniques.