An isocratic reversed phase stability-indicating reverse phase high-performance liquid chromatographic (HPLC) assay method have been developed and validated for the determination of pentoxifylline in bulk drugs. Separation of pentoxifylline from the degradation products was carried out using an Inertsil ODS C18 (250cm x 4.6)mm,5u column  with  mobile phase consisting a mixture of  acetonitrile  and  KH2PO4 buffer (pH 4.0) in the ratio of (60:40v/v). The detection was carried out at wavelength 275nm. The developed method was validated with respect to linearity, accuracy (recovery), precision, system suitability, selectivity prove the stability indicating ability of the method.