A review on the quantitative determination of aromatic monocarboxylic acids (AMCAs), intermediates in the metabolism of the proteinogenic amino acids phenylalanine and tyrosine, in body fluids is presented. The importance of these compounds as potential diagnostic low-molecular-weight biomarkers of some human diseases is described. The main methodical features of current practical solutions in the field of highly sensitive screening of AMCAs in body fluids using chromatography-mass spectrometry and other methods actively used in clinical laboratory analysis are considered. Special attention is paid to the prospects of developing portable tools of therapeutic monitoring of the compounds of interest in biological fluids. <br> Bibliography includes 108 references.