The biological methods for synthesis of nanoparticles by using various microorganisms, enzymes, plants, and their extracts have been suggested as the probable and promising eco friendly alternatives to the chemical and physical methods of synthesis. The biocompatibility of nanoparticles is more essential for specific biomedical applications and researches. The aim of this study was to evaluate the effect of ZnO nano particles for anticancer and antimicrobial activity. In this study ZnO Nano particles were synthesized by Bacillussubtilisusing Zinc acetate dihydrate as substrate and sodium borohydride as reducing agent. The preliminary confirmation of the presence of the nanoparticles was the formation of precipitate and white coloration in the final mixture. The confirmation of the presence of nanoparticles was carried out by SEM analysis. The antimicrobial activity of nanoparticles was determined by well diffusion method and also the synergistic effect of nanoparticles with antibiotics on bacteria was determined by well diffusion method. The anticancer activity of the nanoparticles on MDA MB321 human breast cancer cells was determined by MTT assay. Hanumitha. S | Mahalakshmi. V | Abirami. S "Biosynthesis of Zinc Oxide Nanoparticles Using Bacillus Species Potentiates Anticancer and Antimicrobial Activity" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: https://www.ijtsrd.com/papers/ijtsrd17137.pdf Paper URL: http://www.ijtsrd.com/biological-science/microbiology/17137/biosynthesis-of-zinc-oxide-nanoparticles-using-bacillus-species-potentiates-anticancer-and-antimicrobial-activity/hanumith-s