Equilibrium solubilities of p-quinone (1,4-benzoquinone) and 9,10-anthraquinone at 35 degrees C and 45 degrees C in supercritical carbon dioxide over a pressure range of about (85-300) bar have been measured using a supercritical fluid extractor coupled with a high-pressure Liquid chromatography apparatus. The solubility results, along with those reported in the literature for 1,4-naphthoquinone, are correlated with a modified Peng-Robinson equation of state.