We have investigated the green synthesis and antimicrobial activity of silver nanoparticles using Garcinia kola. Aqueous extract of G. kola was used to reduce AgNO 3 solution to obtain black nanocrystal of silver nanoparticles. Antimicrobial activity of the silver nanoparticles was tested against Escherichia coli, Klebsiella pneumonia, Bacillus subtilis, Staphylococcus aureus, Aspergillus niger, Rhizopus stolonifer and Candida albican. The synthesized silver nanoparticles was characterized using UV-vis spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. UV-visible exhibits prominently the characteristic surface plasmon resonance at around 427 nm. A remarkable particle growth onset of 10 min was observed while the reaction ended within 30 min. The XRD analysis shows that the synthesized silver nanoparticles are crystalline in nature and well-dispersed silver nanoparticles with an approximate size of 10.4 nm were observed on TEM. The synthesized silver was found to possess good antimicrobial activity against all the tested microbes. The application of the green synthesized nanoparticles can be used in many fields such as foods, beverages, cosmetics and medicine.