A simple co-precipitation method at normal temperature was used to prepare Mg and Al co-doped ZnO nanoparticles. The structure and chemical properties of synthesized nanoparticles were characterized by various techniques such as XRD, FTIR, SEM-EDX, UV-Visible Spectroscopy and AFM, whereas the photo-catalysis study of Congo red (CR) was performed by UV/VIS spectrophotometry. The XRD results exhibited that Mg, Al co-doped ZnO nanoparticles possess hexagonal wurtzite structure. The SEM analysis suggested varying nano morphology of synthesized nanoparticles and the purity of the sample was checked by EDX analysis. Mg, Al co-doped ZnO nanoparticles were subjected for the photo-degradation of congored dye (CR) in aqueous medium under UV-light irradiation. The photo-degradation study revealed that the Mg, Al co-doped ZnO nanoparticles is a promising substance for the hazardous ecological remediation.