Al-Zn-Cu mixed oxide nanoparticles was synthesized via sol-gel method by maintaining the pH around 8. Antibacterial activity of mixed oxide and cerium oxide was evaluated against 3 bacterial strains by agar diffusion method. The results revealed that the mixed oxides was moderate activity against all the listed bacteria whereas, cerium oxide showed against Klebsiella only. Thus synthesized mixed oxide possesses improved antibacterial activity than cerium oxide. The zinc oxide possesses low activity against Pseudomonas aeruginosa (10 mm) and E.coli. The antifungal activity tests were carried out by diffusion method for the mixed oxide and cerium oxide . Both cerium and mixed oxides showed moderate activity against Candida albicans whereas, both showed least activity against Candida parapsolisis. Thus, the antimicrobial activity of the synthesized mixed oxide showed moderate activity against the three bacterial and two fungal strains. It possesses good antimicrobial activity. Hence, the mixed oxide could be used as a good redox catalyst and further suggest for medicinal applications.