Summary.A simple, precise, rapid, and accurate liquid chromatography-mass spectrometry (LC-MS) compatible reversed phase high-performance liquid chromatography-photodiode array detection (RP-HPLC-PDA) method has been developed and validated for the estimation of oxcarbazepine (OXC) in bulk and tablet formulations. The chromatographic separation was achieved on Phenomenex C 18 column (150 mm × 4.6 mm, 5.0 μm particle size) using the mobile phase comprising methanol-formic acid (0.02% v/v in water) in the ratio of 50:50 (v/v) at a flow rate of 1 mL min −1 , and OXC was eluted at 6.4 min. Quantification and linearity were achieved at 229 nm over the concentration range of 10-50 μg mL −1 , and the mean percentage of assay was found to be 100.03. The method was validated for specificity, linearity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), stability, and robustness as per the International Conference on Harmonisation (ICH) guidelines and it is suitable to be employed in quality control.