||An isocratic stability-indicating reversed phase liquid chromatography (RP-HPLC-UV) method for quantitative determination of tapentadol HCl has been developed and validated as per the ICH guidelines. Tapentadol HCl and the tablet formulation were subjected to forced decomposition conditions of hydrolysis, oxidation, photolysis and thermal stress, as per ICH guidelines. Thermal, photostability, accelerated and real time stability testing was carried out with the marketed tablet formulation of the drug. An Inertsil ® C-18 (250 mm x 4.6 mm, 5µ) column was used to carry out the chromatographic analysis. The mobile phase composed of methanol-water (pH 2.5 with formic acid of the aqueous part) (35:65 %v/v) (flow rate 1.0 mL/min; Detection wavelength 254 nm). The drug was found to be extremely stable and there was no degradation under various stressor conditions. Excellent linearity was observed in the range of 0.05–5.0 µg/mL (r 2= 0.9998). The limits of detection (LOD) and quantification (LOQ) were 0.0008 and 0.0024 µg/mL respectively. The proposed method gave good recovery of the drug in the tablet formulation as well (100.8 % in control and 98.53 - 99.73 % in the various stability samples).