A reverse phase isocratic high performance liquid chromatographic method was developed for the estimation of bosentan drug in tablet formulation. The separation was achieved by C-18 hypersil250*4.6mm, 5μm and methanol: potassium dihydrogen orthophosphate buffer pH 7.8 (60:40 v/v) as mobile phase, at a flow rate of 0.8 ml/min. Detection was carried out at 220 nm. Retention time of Bosentan was found to be 8.26 +or-1. The method has been validated for linearity, accuracy and precision. Linearity of bosenatan was in the range 50-150 mcg/ml. The mean recovery obtained for was 99.1. Developed method was found to be accurate, precise, selective and rapid for estimation of bosentan in tablets.