Abstract: A simplified method for the determination of isonicotinic acid hydrazide using 0.1N HCl as supporting electrolyte is proposed.Isonicotinic acid hydrazide in 0.1N HCl exhibits two well-defined waves,and their half wave potentials are respec- tively-0.490 and-0.658 volts vs.S.C.E.The diffusion current constants of which were found to be 2.79 and 3.29 respectively.The concentration of isonicotinic acid hydrazide is directely proportional to the diffusion currents in the range of 10^-5 to 10^-2M.