The purpose of this study was to identify and characterize humic compounds in Anticolana Valley (Fiuggi) water. The capacity of this class of compounds to mobilize metals from solid phases could have an important role in calculi solubilization. Humic compounds were isolated, purified and characterised by FTIR, 1H-NMR and 13C-NMR spectroscopy, thermogravimetry and elemental analysis. Only fulvic acids were found. They are mainly composed of aliphatic chains, made of six -CH2O- groups and contain a number of carboxylic groups, responsible for their metal complexing capacity.