A simple, sensitive and precise high performance liquid chromatographic (HPLC) method was developed and validated for determination of flavoxate HCI in raw material, tablets and biological fluids. The method followed by using the Zorbax XDB-C18 column containing Di-isobutyl n-octadeceylsilane (4.6mmx150mm, 5 mu m). The mobile phase consisted of acetonitrile: methanol: 0.15M sodium perchlorate (17:35:48 v/v) having pH 3. UV detection was carried out at 229nm at 40 degrees C. Results indicated that the method has successfully established and validated in accordance with ICH guidelines acceptance criteria for linearity (0.03-7.5 mu g), accuracy (101.18-101.28%), robustness of column age and column lot (peak area %CV <= 0.04, purity %CV <= 0.006) and robustness of HPLC condition (%CV <= 0.02), precision (intra and inter day precision assay, %CV values for peak area and percent purity of flavoxate HCl <= 2%) and system suitability parameters. The average noise, theoretical LOD and LOQ were found to be 0.01 mAU, 0.03 mAU and 0.6ng, respectively. The Coefficient of determination (r(2)) ranging from 0.03 mu g to 7.5 mu g, 0.99 which was within acceptable criteria of r(2) & gt 0.99. The spiked recoveries of samples were 101.28, 101.18 and 101.18% respectively. All data revealed that this method can be used for in-vitro & in-vivo determination of flavoxate HCI in various pharmaceutical preparations.