A new method and a rigorous procedure are proposed for the determination of the solubility of aliphatic amines (AA) in water. The method is based on cyclic voltammetry (CV). CV titrations were performed at acidic buffered pH at a controlled ionic strength (I). In those conditions the AA are completely soluble and nonvolatile. The pH and I control is necessary to obtain rigorous thermodynamic data, and it allows to avoid some possible procedural errors which can be highlighted in the reported solubility data. The solubility constants of tri-n-propylamine, tri-n-butylamine, and tri-n-isobuthylamine were obtained at 25 degrees C and resulted to be (1.7 +/- 0.1).103, (2.7 +/- 0.5).105, and (3 +/- 1).107, respectively. From these constants, the solubility values of 6.7 +/- 0.8 mM, 0.95 +/- 0.09 mM, and 0.044 +/- 0.008 mM, respectively, were computed. The proposed method allowed to determine thermodynamic results also for the poorly water-soluble tri-n-isobuthylamine, for which no solubility data were hitherto available in the literature. The experimental results evidenced that the proposed approach based on CV titrations is reliable and simple and that it is better suitable than other available methods for the determination of the solubility of poorly water-soluble AA.