A sensitive method for the determination of the herbicide dimethametryn by adsorptive stripping voltammetry using a hanging mercury drop electrode at pH 4.0 was described. The cyclic voltammogram of dimethametryn demonstrate that compound was adsorbed at the surface of mercury electrode and the overall reduction process was under controlled diffusion. The adsorptive peak was observed at -0.9V and peak response was measured with respect to pH, accumulation time, potential, and scan rate. The calibration plot was found to be linear from the concentration range 3.0×10-9 to 4.0×10-7 mol/L with a detection limit 2.0×10-9. Also interference of some other pesticides on dimethametryn determination was evaluated. Finally the developed method was potentially applied for determination of dimethametryn in soil and water samples.