The determination of 2,4-dinitrophenol (DNP) by stripping voltammetry with a hanging mercury drop electrode was studied. The experimental conditions such as pH, supporting electrolyte, accumulation potential and accumulation time were optimized. In these conditions, the sharp peak of DNP appeared at -0.348 V. The peak current of DNP was proportional to the concentration of DNP in the range of 0.03 - 0.75 mgIL. The limit of detection of DNP in water sample was 0.00917 mg/L and its limit of quantity was 0.03057 mg/L.