A spontaneous, one-pot strategy for the room temperature synthesis of gold nanoparticles (AuNPs) using Cocos Nucifera Linn (coconut palm) coir extract is described. The formation of AuNPs was observed within 30s of reaction time between the metal precursor and coir extract. The bioextract acted as both reducing agent and a stabilizer. The influence of various experimental parameters such as % volume fraction of coir extract, concentration of metal precursor, contact time and solution pH on the formation of AuNPs was evaluated to determine the optimum conditions for synthesis. As synthesized AuNPs were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX), Fourier transform infra red spectroscopy (FTIR) and electrophoretic mobility measurements. The analyses indicated the formation of spherical, crystalline, nanometer-sized particles carrying negative surface charge due to the presence of various functional groups from coir extract. The possible mechanism of the formation and stabilization of AuNPs is discussed. The catalytic activity of AuNPs for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride was investigated. Moreover, the present synthetic strategy can be extended to prepare the nanoparticles of other metal ions such as silver and platinum.