A stability indicating reversed-phase liquid chromatography method is developed and validated for the determination of norfloxacin in a new formulation of extended-release tablets. The LC method is carried out on a Luna C(18) column (150 x 4.6 mm) maintained at 40 degrees C. The mobile phase is composed of phosphate buffer (0.04 M, pH 3.0)-acetonitrile (84:16, v/v) run at a flow rate of 1.0 mL/min and detection at 272 nm. The chromatographic separation was obtained within 10 min, and it is linear in the concentration range of 0.05-5 microg/mL. Validation parameters, such as the specificity, linearity, precision, accuracy, and robustness, were evaluated, and results were within the acceptable range. Moreover, the proposed method was successfully applied for the assay of norfloxacin in the developed formulations.