The phase behaviour of the pyrrole-carbon dioxide binary system was investigated in a variable volume view cell (vvvc) with a synthetic method. The experimental results were correlated by the Peng-Robinson equation of state using the Mathias-Klotz-Pi-ausnitz mixing rule. This work was focused at the temperature- and pressure ranges of 313-343 K and 7-17 MPa, covering the conditions where the impregnation of different polymer substrates with pyrrole is the most likely feasible. According to the extrapolated results of the model in addition to the experimental data, the liquid-liquid immiscibility ceases above the more volatile component's critical temperature and pressure. This kind of phase behaviour was classified type-III by van Konynenburg and Scott. (C) 2008 Elsevier B.V. All rights reserved.