CuO nanoparticles (NPs) were prepared by Convolvulus percicus leaves extract as a reducing and stabilising agent. The green synthesised copper oxide NPs was characterised by transmission electron microscope, energy dispersive X-Ray spectroscopy, X-ray diffraction, Fourier transform infrared and ultraviolet-visible analysis. The activities of the CuO NPs as catalyst were tested in the formation of C-N and C-O bonds. The N-arylated and O-arylated products of amides, N-H heterocycles and phenols were obtained in excellent yields. Furthermore, the separation and recovery of copper oxide NPs was very simple, effective and economical. The recovered catalyst can be reused several times without significant loss of its catalytic activity. Moreover, the antibacterial activity of these NPs was tested against two human pathogenic microbes and showed significant antimicrobial activity against these pathogenic bacteria.