The experimental determination of high-pressure phase equilibria is often the only suitable method to obtain reliable data because high-pressure phase behavior is complex and difficult to predict. This contribution gives a brief classification of applied experimental methods. A new high-pressure apparatus is described, which can be used for phase-equilibrium measurements with different experimental methods, namely the analytical-isothermal method, the synthetic-isothermal method as well as the non-visual- and the visual-synthetic method. The different techniques have been tested for the measurement of the phase behavior of systems containing CO2 + styrene and CO2 + vinyl acetate. The measured data were compared with data from literature and discussed in terms of accuracy, advantages and drawbacks of the applied methods. (C) 2010 Elsevier B.V. All rights reserved.