High pressure phase equilibria for the (carbon dioxide + valeronitrile), (carbon dioxide + capronitrile) and (carbon dioxide + lauronitrile) systems are measured in static apparatus at five temperatures of 313.2, 333.2, 353.2, 373.2 and 393.2 K and pressures up to 25.7 MPa. The three carbon dioxide + nitrite systems have continuous critical mixture curves that exhibit maximums in pressure at temperatures between the critical temperatures of carbon dioxide and nitrites. The solubility of valeronitrile, capronitrile and lauronitrile for the (carbon dioxide + nitriles) systems increases as the temperature increases at a fixed pressure. The (carbon dioxide + valeronitrile), (carbon dioxide + capronitrile) and (carbon dioxide + lauronitrile) systems exhibit type-I phase behavior. The experimental results for the (carbon dioxide + valeronitrile), (carbon dioxide + capronitrile) and (carbon dioxide + lauronitrile) systems are correlated with Peng-Robinson equation of state using a mixing rule including one and two adjustable parameters. (C) 2011 Elsevier B.V. All rights reserved.