Because of its medical and biological uses, green nanoparticle production has gotten a lot of attention. Bismuth oxide nanoparticles (Bi2O3 NP) were synthesized using aqueous extract from cocoa plants in this study, and the result was examined using an ultraviolet-visible, spectro-photometer, Fourier transform infrared, X-ray diffraction, and atomic force microscopy, The samples’ antibacterial activity was tested against a variety of microorganisms.