A Sensitive, rapid and selective spectrophotometric method was developed for the determination of sulfacetamide sodium in an aqueous solution. The method is based on the oxidative coupling reaction with 2,4-dinitophenylhydrazine in the basic medium in the presence of potassium periodate to produce an intense orange colour product, soluble in water, stable and gives maximum absorbance at 484 nm. The linearity of Beer's law was in the range of 2.5-75 μg/ml of sulfacetamide. The molar absorptivity, Sandellʼs sensitivity, and detection limit were 3202.92 L/mol.cm, 0.07936 µg/cm2 and 0.50476 μg/ml respectively. This method is applied successfully to the determination of sulfacetamide in pharmaceutical preparation (eye drops and ointment).