A fast method was developed for simultaneous detection and quantification of 12 phenolic compounds in mung bean, using reversed phase high-performance liquid chromatography. The method was optimized for mobile phase combination, elution gradient, detection wavelength, and solvent extraction. All the phenolic compounds (gallic acid, neochlorogenic acid, catechin, chlorogenic acid, caffeic acid, p-coumaric acid, t-ferulic acid, vitexin, isovitexin, myricetin, quercetin, and kaempferol) were eluted for 18 min and recovered within a limit as per International Council for Harmonization guidelines. The method showed good linearity with correlation coefficient of 0.998. The limit of detection and quantification of all the compounds ranges from 0.27 ± 0.01 to 3.65 ± 0.3µg/mL and 0.91 ± 0.1 to 12.17 ± 0.9µg/mL, respectively. Vitexin (28.10 ± 0.20 to 29.60 ± 0.6 mg/100 g raw material) and isovitexin (34.09 ± 0.14 to 36.83 ± 0.82 mg/100 g raw material) were the major phenolic compounds along with other phenolic compounds found in mung beans.