A reversed-phase high-performance liquid chromatography diode array detector (HPLC-DAD) method was developed for the separation of triterpene acids and their determination in crude extracts of Potentilla species. Symmetry octadecylsilyl silica (ODS) column with acetonitrile and water with phosphoric acid (pH = 2.5) as the mobile phase was used in the described HPLC system. The column temperature was at 20 °C, the flow rate was 0.8 mL/min. The detection wavelength was 210 nm. For quantitative purposes, the linear dependencies of analyte concentration and peak surface area were obtained with regression coefficient values 0.9983 < r 2 < 0.9995. For euscaphic acid, calibration was performed in the range of 0.07–0.525; 0.7–2.1 mg/mL, for pomolic acid in the range of 0.019–0.171; 0.209–0.665 mg/mL, for ursolic acid in the range of 0.2–1.375–3.3 mg/mL. The observed recovery of triterpene acids was from 95.3% to 103.1%. The observed values of RSD were well within the generally acceptable limit of no more than 5%. This method was successfully applied to quantify pomolic acid (PA), ursolic acid (UA) and the sum of euscaphic (EA) and tormentic acids (TA) (expressed as euscaphic acid) in roots and rhizomes of 15 various Potentilla species and 2 subspecies (i.e., P. atrosanguinea, P. recta).