Nowadays, green chemistry attracts the attention of analysts to develop methods that do not rely on hazardous chemicals, which negatively affect humans and the environment. Thus, an environmentally safe, sensitive, and selective HPLC technique was established for the analysis of commonly formulated water pills; Xipamide (XIP) and Triamterene (TRI), which are prescribed usually to treat hypertension in combination with the toxic impurity of TRI; Benzyl cyanide (BC). The assay of this water pills binary mixture was performed using several analytical techniques. Still, none of them paid attention to assay the related toxic impurity or evaluate the method's greenness. We utilized the HPLC C₈ column to resolve the ternary mixture using methanol and 50 mM phosphate buffer in the ratio of (50: 50 by volume, pH 4.5) as a mobile phase, delivered at 1.2 mL min^-1 and 220 nm was selected for detection of the eluate. Calibration curves were constructed in the range of (1-100 μg mL^–1) for TRI and XIP, and (5-50 μg mL^–1) for BC. Limit of detection was calculated to be 0.30 μg mL^–1, 0.45 μg mL^–1, 3.2 μg mL^–1 for TRI, XIP and BC, respectively. The greenness profile of the suggested method was evaluated using the analytical eco-scale. Following the ICH requirements, the recommended method was validated and used to analyze the marketed formulations. The obtained results encourage the quality control laboratories to adopt the proposed approach routinely with the lowest harm to the environment.