A simple and cost effective, fast and precise reverse phase high performance liquid chromatographic method is described for the determination of zonisamide in pure form and in pharmaceutical formulations. This method is based on using a Luna 5μ C18 column and the size of coloum is 5 micron, 250 x 4.60 mm from phenomenex. Mobile phase is methanol: phosphate buffer (pH adjust to 3.5 ± 0.1 with ortho-phosphoric acid), the ratio of mobile phase is 65 : 35 v/v, the flow rate is 1 mL / min, and effluent was monitored at 285 nm. The elution time was 8.5 min. The linearity range was 10-60 μg/mL for zonisamide.