<p>Two different methods have been developed for the quantification of gliclazide in pharmaceutical products using the HPLC technique. While acetonitrile was employed in the mobile phase of the standard method as an organic modifier, in the green method’s mobile phase, ethanol was utilized. Formic acid solution (0.1% in ultrapure water) and acetonitrile (40/60, v/v) were used as the mobile phase. The isocratic elution was performed at a flow rate of 1.0 mL min^-1, and 10 μL of active substance was injected into the column and measured at 226 nm UV detector. In the green method, ethanol was used as an organic modifier and all other conditions were identical to those of the classical method. Both chromatographic techniques were validated in accordance with ICH principles for a number of criteria, including robustness, selectivity, accuracy, linearity, and detection and quantification limits. In the concentration range of 5–30 mg mL^-1, the correlation coefficients of the chromatographic techniques were more than 0.999. The chromatographic methods were applied to pharmaceutical formulations. While the Student’s (<i>t</i>) test for means and the Fischer (<i>F</i>) test for standard deviations were used to compare the results, no significant difference was found between these methods. These two methods were then evaluated using the AGREE greenness assessment software. The green method was proposed as an excellent eco-friendly and analyst-friendly alternative for gliclazide quantification in pharmaceutical formulations.</p>