A simple, economical, sensitive, specific, precise and accurate RP-HPLC method was developed and validated for determination of Zileuton in bulk and pharmaceutical dosage form. Chromatography was carried on an Enable C18 G 250 x4.6 mm column using filtered and degassed mixture of methanol and water (70: 30 v/v) as mobile phase at a flow rate of 1.0 ml/min in isocratic mode and effluent was monitored at 229 nm. The retention time for zileuton was found to be 3.5 min. The method was linear over the concentration range of 5-30 Cg/ml with correlation coefficient 0.999. Proposed method was validated for specificity, precision, accuracy, linearity, robustness.