Response surface methodology (RSM) was employed to optimize the process parameters of supercritical carbon dioxide extraction of the passion fruit seed oil. The effects of temperature, pressure and extraction time on the oil yield were investigated. Results showed that the data were adequately fitted into the second-order polynomial model. The linear and quadratic of independent variables, temperature, pressure and extraction time, the interactions between temperature and extraction time, pressure and extraction time had a significant effect on the oil yield. It was predicted that the optimum extraction process parameters within the experimental ranges would be the extraction temperature of 56 degrees C and pressure of 26 MPa and extraction time of 4 h. Under these conditions, the oil yield was 25.83%. The color of passion fruit seed oil extracted by supercritical carbon dioxide is golden orange. Its physical and chemical properties come up to the required standard for edible oil. The content of unsaturated fatty acid in passion fruit seed oil was up to 89.43% and the content of linoleic acid was over 72%. (C) 2008 Elsevier B.V. All rights reserved.