The use of different plant materials for the green synthesis of metal oxides is considered as an environmentally friendly method, since it does not involve the use of toxic chemicals and harsh conditions. In this study, zinc oxide (ZnO) particles were synthesized using aqueous leaf extract of Ziziphus mauritiana Lam. Synthesized ZnO particles were characterized using X-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Antioxidant activities of the as-prepared ZnO were evaluated using 2-2-diphenyl-1-picrylhydrazyl radical (DPPH·) assay, with varying ZnO concentration. The synthesized ZnO was found to effectively scavenge DPPH·. Antibacterial studies using agar disc diffusion method showed that the synthesized ZnO particles with concentration of 25, 50, 100, 200 and 400 mg/mL showed antibacterial activities against Staphylococcus aureus, whereas no antibacterial activities were observed against Escherichia coli. Hence, phytogenically synthesized ZnO could be a potential candidate for different biological applications.