High pressure cloud-point data were reported for poly(2-butoxyethyl acrylate) [P(2-BEA)] in propane (C3H8), propylene (C3H6), butane (C-4-H-10), 1-butene (C4H8), and dimethyl ether (DME) (CH3OCH3), as well as for the P(2-BEA) + 2-butoxyethyl acrylate (2-BEA) (or DME) system in supercritical CO2. Cloud-point pressures for the P(2-BEA) + C-3 hydrocarbons curves were ca. 22 MPa higher than those for P(2-BEA) + C-4 hydrocarbons, at a constant temperature of ca. 393 K. The cloud-point pressure for the P(2-BEA) + DME system was located between C-3 and C-4 hydrocarbons at pressures below ca. 20.0 MPa. The P(2-BEA) + CO2 + 0.649 and 0.680 2-BEA phase behavior curves intersect a one phase (fluid) -> two phases (liquid + vapor) curve at temperatures of 353.6 K (at 24.5 MPa) and 413.4 K (at 32.3 MPa). The location of the P(2-BEA) + CO2 cloud-point curve shifts to lower temperatures and pressures upon the addition of 2-BEA or DME. Vapor-liquid phase equilibrium data at high pressures were presented for the CO2 + 2-BEA system at temperatures ranging from (313.2 to 393.2) K and pressures up to 20.38 MPa. The CO2 + 2-BEA system exhibits type-I phase behavior with a continuous critical mixture curve and was adequately modeled using the Peng-Robinson equation of state.