Objectives: The development and optimization of a method used for the quantitative and qualitative determination of cryptochlorogenic and neochlorogenic acid using ultra-highperformance liquid chromatography coupled with mass spectrometry (UHPLC-MS/MS), followed by the validation of the method itself to ensure the reliability of the results. Materials and methods: The working standard used in the research was a mixture of cryptochlorogenic and neochlorogenic acids, from which solutions with concentrations ranging from 0.005 mg L-1 to 50 mg L-1 were prepared. These solutions were then used for the development and validation of liquid chromatography and mass spectrometry method. Results: To prepare lower concentrations, the standard solution was diluted with methanol. The mobile phase consisted of a mixture of water and methanol mixed with 0.2% volume fraction of acetic acid as a modifier. An Agilent column packed with C18 stationary phase was selected and the analysis was carried out at 25 °C. The mass spectrometer was optimized by setting the capillary voltage to 4400 V for both acids. RF lenses were adjusted to 110 V for cryptochlorogenic and 109 V for neochlorogenic acid. The temperature of the gas used to form the fine mist was 350 °C, and the temperature of the ion transfer capillary was maintained at 325 °C. The spectra were recorded in the negative ionization mode, and the method enabled the understanding of the fragmentation of chlorogenic acids by analyzing the MS/MS spectrum. The evaluation of the method yielded satisfactory results. Conclusions: Ultra-high performance liquid chromatography coupled to a triple quadrupole mass spectrometer is a suitable method for the determination of cryptochlorogenic and neochlorogenic acid, and the validation confirmed its application.