Phenolic acids and phenylpropanoids have an important biological activity and are therapeutic agents of crude drugs. Development of validated analysis techniques of these phytotherapeutic agents (fingerprinting and assay procedures) is an important practice for efficacy, safety, and quality control of herbal drug preparations. The aim of the present work was to study analytical capabilities of the evaluation of selected phenolic acids and phenylpropanoids: caffeic acid, chlorogenic acid, cinnamic acid, coumaric acid, ferulic acid, gallic acid, protocatechuic (3,4-dihydroxybenzoic) acid, rosmarinic acid, vanillic acid, and vanillin. Optimization and validation procedures of rapid and simple method of reversed-phase high-performance liquid chromatography were carried out. The mobile phase of the optimized chromatographic method consisted of methanol and 0.5% acetic acid solvent in water. For the application of method, two kinds of raw materials were chosen: propolis and the Herba Origani. Coumaric acid is the dominating phenolic acid of propolis (2785 microg/g). Results of analysis of Herba Origani demonstrated high quantities (6376 microg/g) of rosmarinic and protocatechuic (1485 microg/g) acids in the samples.