The ability of certain monoterpenes from the essential oils of Abies sachalinensis and Eucalyptus species to dissolve polystyrene (PS) was studied. These two essential oils themselves were also examined. The aim of this study is to recycle PS without a melting process and without using petroleum-derived solvents. The relationship between chemical structure of the terpenes and their dissolving power for PS is investigated through the solubility parameter and apparent activation energy for dissolution. a-Terpinene and its positional isomers on a C=C bond have high solvent powers for PS, whereas bicyclic terpenes are inferior in this regard even though they have similar solubility parameters to that of alpha-terpinene. It is suggested that the bulky and/or hydrophilic structures in the solvent molecule prevent the dissolution of PS. Simple steam distillation of solutions of PS in the terpenes gave recovery of more than 97% of the PS and terpenes. The present solvent systems cause little degradation to PS and are promising for the recycling of PS using sustainable solvents. (C) 2008 Wiley Periodicals, Inc. Adv Polym Techn 27: 35-39, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20115