Nickel nanoparticles has been synthesized using nickel chloride as a precursor and coriander leaf extract as a reducing agent and stabilizing agent at room temperature under ordinary condition. The progress of the reaction was monitored most probably observing change in colour of obtained solution. The synthesized nickel nanoparticle was confirmed by UV-Vis, FTIR and powder XRD techniques. The size of nanoparticle was determined by using powder XRD and found to be 30.71 nm. The merits of this method are easily available material and inexpensive starting material, short reaction time, easy to carry out.