This article reports experimental density values of aqueous 3-dimethylamino-1-propanol (3DMA1P) solutions over the entire range of 3DMA1P mass fractions and temperatures of (293.15 to 343.15) K. Based on the experimental results, corresponding values of thermal expansion and excess molar volume of 3DMA1P solutions were established. A second order Redlich–Kister polynomial equation satisfactorily correlates excess molar volumes against mole fractions of 3DMA1P solutions, and regression of these parameters as a function of temperature is demonstrated. Densities of carbonated 3DMA1P solutions were also measured at three 3DMA1P mass fractions of 0.20, 0.30 and 0.50, at different CO2-loadings up to 0.8 mol CO2/mol 3DMA1P, and temperatures. These data were modeled. A comparison between experimental and calculated values are discussed.