Many phenolic-flavonoids found in plants exhibit antipyretic, analgesic, anti-inflammatory & antioxidant properties. Twelve phenolic compounds namely Ellagic acid, Catechol, Gallic acid, Quercetin, Resorcinol, Tannic acid, Vanillin, Salicylic acid, Acetyl Salicylic acid, Benzoic acid, Phloroglucinol and Ascorbic acid were taken up for qualitative and quantitative HPLC analysis. The objective of this research was to determine the standard HPLC chromatograms of twelve prominent phenolic compounds found in medicinal plants using four mobile phases having different elution gradients and run times. Six mg of each standard compound was dissolved in 10 ml Methanol, sonicated and passed through Membrane Filter (0.45μm & 47mm diameter) before injecting 20 μl in Column: Symmetry C18 (5μm, 4.6*250mm) & flow rate 1.0 ml/min. UV-detection at 280 360 nm was performed using 515 HPLC pumps and 2489 UV/VIS detectors. Four HPLC methods using different mobile phases were used. Methods A & B used varying ratios of Methanol and Acetic acid as solvents, the runtime being 22 and 25 minutes respectively. Similarly methods C and D used Acetonitrile and Phosphoric acid, run times being 30 and 45 minutes. All the methods resulted in similar pattern and sequence of elution of these phenolic compounds as unique chromatographs when analyzed individually and together. These HPLC fingerprints of standard phenolic compounds could be used as benchmarks for comparison during the qualitative and quantitative analysis of unknown compounds present in any plant sample. Use of multiple methods involving different phases would increase the validity and reliability of results.