Supercritical and compressed liquid CO2 extraction of thin solid organic films was studied using in situ capacitance monitoring. Parallel plate and fringe field capacitors were fabricated using organic films as principal dielectric media. Supercritical and compressed liquid CO2 extraction of these films at 100 bar and 30–45°C caused compositional and physical changes in the host polymer matrix that were correlated to capacitance history. As a result of these studies, film damage during extraction was attributed to explosive decompression of the CO2 solvent. In addition, a mechanism for supercritical fluid extraction of nonvolatile solutes from thin films, which is consistent with these capacitance measurements, is discussed.