The present research work characterizes aqueous solutions of amines with possible implementation in acidic gases separation processes, regarding different physical properties. Specifically this study compares the behavior of aqueous solutions of a diamine (3-dimethylamino-1-propylamine + water, DMAPA) and ternary mixtures using aqueous amine blends (3-amino-1-propanol, AP + 3-dimethylamino-1-propanol, DMAP + water) with the same type and number of amino groups. These experimental data contribute useful information to analyze the most suitable system with respect to the physical properties, to be used in operations controlled by mass transfer. The binary system composed of the two amines used for the tertiary system (3-amino-1-propanol + 3-dimethylamino-1-propanol) has also been studied. The studies analyze the influence of mixture composition and temperature upon several properties such as density, speed of sound, dynamic viscosity, and surface tension. On the basis of these studies, some significant differences have been observed that can cause important effects on the behavior of mass transfer-based separation processes.