In the current work, we followed a green chemistry route to prepare and characterize the silver nanoparticles (AgNPs) using Syzygium aromaticum (clove) extract at room temperature. Suitably, the clove extract acted as a reducing agent as well as a capping agent, and these reactions occurred rapidly. The formation of the AgNPs was confirmed by the observation of the distinct absorption peak at a wavelength of 418 nm using ultraviolet–visible (UV–Vis) spectroscopy, and a morphological study confirmed the uniform distribution of the optimally spherical nanoparticles. Fourier transform infrared spectroscopy (FTIR) results indicated the methoxy and allyl functional groups of eugenol of the clove extract to be responsible for the bioreduction of silver ions and for the stabilization of the resulting nanoparticles (flavonoids). We also found the AgNPs to be effective catalysts of the degradation of three pollutant organic dyes viz., 4-nitrophenol, methylene blue and rhodamine B, in the presence of excess NaBH 4 . The antibacterial and antifungal activities of the bio-synthesized AgNPs were also explored. Overall, the results suggested the potential use of clove extract as a resource for the synthesis of AgNPs having a broad range of possible commercial and biomedical applications. © 2019 John Wiley & Sons, Ltd.