This study examines the effects of pressure, temperature and solvent to solid ratio (SSR) on extraction efficiency of triglycerides from powdered Aquilaria crassna seeds by using supercritical carbon dioxide (SC-CO2) extraction. Supercritical extractions were designed for pressures ranging from 250 to 350 bar, temperatures ranging from 313 to 333 K and SSR values ranging from 60:1 to 120:1. All values were selected using response surface methodology (RSM) in order to determine their effects on the concentration of triglycerides from the SC-CO2 extracted oil. Using 3000 g of carbon dioxide over 4 h, a supercritical carbon dioxide extraction (at 310 bar, 333 K and an SSR value of 100:1) yielded 33.99% oil having the concentration of triglycerides of 568.3 mg/g. The extraction efficiency (i.e. recovery) of triglycerides reached 96.77%. Changes in pressure presented more effective in increasing the recovery of triglycerides. Both temperature and the SSR value are important in obtaining high concentration of triglycerides from the A. crassna seeds that are potential for biodiesel materials. (C) 2010 Elsevier B.V. All rights reserved.