Different chemo-physical methods are used to synthesise titanium oxide nanoparticles (TiO NPs), which are often expensive, unfriendly to the environment, toxic, not biocompatible, with a small yield. To resolve these problems, the researchers use green procedures to synthesise TiO-NPs by plant extracts of L. and (onion) and characterise using atomic force microscopy, scanning electron microscopy, transmission electronic microscopy, X-ray diffraction, ultraviolet (UV)-visible (Vis) spectra and Fourier transform infrared spectroscopy. The results indicate that most NPs synthesised by the first and second procedures of onion had an average diameter of 95.7 and 89.1 nm, while NPs synthesised by had an average diameter of 103.60 and 90.07 nm, respectively. In UV-Vis spectra, strong absorption was below 470 nm, and energy gap was 3.3 eV in each of the first procedure of and the second procedure of compared with 270 nm, 6.3 eV for each of the second procedure of and the first procedure of . The antimicrobial activities of NPs were evaluated and an attempt was made to enhance these activities by plant's oil in combination therapies. There were synergistic effects between NPs and plant's oil.