An adsorptive differential pulse cathodic stripping voltammetry method has been developed for determining the presence of sulfadiazine drugs. The method is based upon the adsorptive collection of the drug on a hanging mercury dropping electrode at −1.0 V versus Ag/AgCl reference electrode. Factors affecting the stripping performance such as, pH, accumulation time and potential, sweep rate were critically studied. The optimum conditions were achieved in a Britton–Robinson buffer of pH 5–6. At the optimal conditions, the cathodic stripping current of the drug at −1.0 V versus concentrations was linear in the concentration range \({3.7 \times 10^{-9}}\) –\({1.0 \times 10^{-7}\;{\rm mol L}^{-1}}\). The lower limit of detection and quantification of the drug were \({1.1 \times 10^{-9}}\) and \({3.7 \times 10^{-9} {\rm mol L}^{-1}}\), respectively. The method was successfully applied for the determination of industrial wastewater, pure form (\({98.2 \pm 3.1}\) %) and drug formulations (\({98.3 \pm 2.9}\) %). The method was validated by comparison with the standard HPLC and the reported methods. The method offers a simple system, coupled with good reproducibility, accuracy, ruggedness, and cost-effectiveness.