Zinc is an essential trace element that widely exists in human body and play a major role in nucleic acid synthesis, protein metabolism etc. Nano zinc can be easily absorbed by the human biological system. In this study, green synthesis of zinc oxide nanoparticles was achieved by Cardiospermum leaf extract which act as reducing and capping agent. The synthesized silver nanoparticles were characterized by UV-Visible spectroscopy, TEM-SAED, XRD, FTIR. UV Visible spectra shows the maximum absorbance peak at 320nm which confirms the formation of zinc oxide nanoparticles. TEM-SAED analysis reveals the hexagonal shape of zinc oxide nanoparticles and size of about 37nm. The XRD spectra reveals the (fcc) cubic crystal structure of the zinc oxide nanoparticles. The peak at 553.57c m−1 in FTIR analysis depicts the characteristic ZnO NPs synthesis. The Cardiospermum mediated Zinc oxide nanoparticles shows substantial antibacterial, antifungal, antioxidant activity in dose dependent manner.