The development and validation of a novel, simple, and quick HPLC technique for measuring bosentan in pharmaceutical formulations was performed. The technique parameters were tuned to be 1 mL/min flow rate, variable column temperature, and a mobile phase combination of methanol-acetonitrile-water (20:50:30 v/v/v) to carry out this study. All measurements were carried out with a UV detector at a wavelength of 272 nm. Specificity, the limit of quantitation (LOQ), limit of detection (LOD), linearity, accuracy, precision, stability, recovery, and ruggedness were all tested. The technique was linear between 0.25 and 20 µg/mL, with precision (RSD%) and accuracy (RE%) of less than 3.0 and 2.7%, respectively. The LOQ and LOD values of method were 0.25 and 0.1 µg/mL, respectively. The 10 µg/mL of standard bosentan solution was found to be moderately stable in acidic and basic settings (0.1 M HCl and 0.1 M NaOH) but unstable in an oxidative environment (H2O2 solution; 3%). No interference from tablet excipients was observed in the HPLC method. The approach was successfully applied to pharmaceutical formulations obtained from a local pharmacy store.