Rapid and accurate isocratic reverse phase high performance liquid chromatography method is described for simultaneous determination of aceclofenac and thiocolchicoside in the combination dosage form. The separation of two drugs was achieved on Thermo Hypersil BDS C18 (250 mm X 4.6 mm) column of 5 µm particle size. Mobile phase consisted of 42:58 of acetonitrile and buffer of pH 6 respectively. Detection was carried out at 261 nm. Thermo Hypersil BDS C18 column showed most favorable chromatographic parameters for analysis. The method was validated for system suitability, linearity, accuracy, precision, robustness and stability of sample solution. The linear range for aceclofenac and Thiocolchicoside was 25-125 μg/ml and 1-6 μg/ml respectively.