Liquid densities for the propylene (1) + 2-propanol (2) + water (3) mixture have been determined at (300, 325, and 350) K from 10 MPa down to about the bubble pressures and for the molar fractions (x(1) = 0.09; x(2) = 0.37), (x(1) = 0.18; x(2) = 0.38), (x(1) = 0.30; x(2) = 0.50), (x(1) = 0.39; x(2) = 0.42), and (x(1) = 0.61; x(2) = 0.30) using a vibrating tube densimeter. The measured liquid density values have been correlated with a multilayer feedforward neural network (MLFN) function including liquid densities values of the propylene + 2-propanol mixture, of the 2-propanol + water mixture, and of the pure components in the temperature range from (300 to 350) K and in the pressure range up to 10 MPa. The consistency of the ternary mixture measurements with those of the binary mixtures and with pure fluids data is very good. The MLFN model shows an accuracy of the same magnitude of the claimed experimental uncertainty for the experimental density measurements.