The present study investigates the green synthesis of Ag nanoparticles (Ag NPs) via the mediation of the extract of Thymbra spicata leaves. In this synthesis, no stabilizers or surfactants were utilized. Field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), and UV-Vis were applied to characterize the green Ag NPs synthesized. It was observed that the Ag NPs/Thymbra is a useful nanocatalyst which can decrease different dyes, including 4-nitrophenol (4-NP), Rhodamin B (RhB), and Methylene blue (MB) in the presence of NaBH4 in water at room temperature. With the help of UV-Vis spectroscopy, catalysis reactions were examined. Furthermore, these reactions followed the pseudo-first order rate equation. (C) 2017 Elsevier Ltd. All rights reserved.