Stability indicating RP-HPLC method for estimation of Tenofovir Disoproxil Fumarate in the presence of its degradation products during conduction of stability studies on the pure drug which was carried out by using a mobile phase comprising ACN: Water (70:30 v/v), pH adjusted to 4.5with OPA, at flow rate of 1 ml/min. with UV detection at 260 nm. The concentration of TDF was found sufficient for obeying Beers law over a range of 10-90μg/ml. In the present study, the drug was subjected to acid (0.1N HCl and 0.01N HCl), and alkaline (0.1N NaOH and 0.01N NaOH) hydrolysis. TDF was found to be more sensitive to alkaline hydrolysis and it was somewhat stable to acidic conditions. The degradation kinetic of Tenofovir Disoproxil Fumarate is governed by hydrolysis of the isopropyloxycarbonylmethyl moiety. Degraded product formed is monoester. The % degradation in both acidic and alkaline condition is calculated by UV-Spectrophotometric and RP-HPLC method.