Ruthenium oxide nanoparticles (RuO2 NPs) are one of the most promising materials at nanoscale, for energy storage devices. In the present work, a bottom up approach was utilized to synthesize RuO2 NPs using biological resources, as reducing agent. Root extract of traditionally important medicinal plant, Akarkara (Anacyclus pyrethrum), was used in this study as the reducing agent. The investigation was carried out without the addition of any external reaction catalyzing agent. The Characterization studies were performed to analyze the conformational nature of the nanoparticles through XRD, SEM, TEM with SAED and FTIR spectroscopy was done to assess the functional moieties. Cyclic voltammetric (CV) studies were carried out to investigate the electrochemical potential of the synthesized RuO2 NPs using the extract. The results demonstrated that the biologically reduced nanoparticles were crystalline, spherical and with an average size of 13 nm. The RuO2 NPs were observed to be highly stable even after repeated usage. CV analysis revealed that capacitance behavior was reversible in nature and the specific capacitance of RuO2 NPs using Akarkara (Anacyclus pyrethrum) coated over carbon sheet was 209 Fg(-1) at a scan rate of 5 mV/s. These results proved that green biosynthesis of RuO2 can be used for supercapacitor applications. (C) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.