Secondary metabolites of solvent extracts of Origanum vulgare subsp. hirtum and O. vulgare subsp. vulgare were determined using liquid chromatography-mass spectrometry (LC-MS/MS). Curcumin was used as an internal standard. Rosmarinic acid was determined as the main compound of studied extracts together with other phenolic acid derivatives. In LC-MS/MS analyses, relative standard deviations (RSD %) ranged between 0.11-9.47. The correlation values were found to be greater than 0.97 for each investigated analyte.