Extraction with supercritical carbon dioxide (SC-CO2) which is known as a clean technology was carried out to extract oil from melon (Cucumis melo) seeds. SC-CO2 extraction technique does not contaminate extracts. SC-CO2 is not a toxic and a flammable solvent. Phytosterols, natural and bioactive compounds, which is known to provide protection against various chronic diseases were examined in the seed oil by using gas chromatography mass spectrometry (GC-MS). Stigmasterol and beta-sitosterol were detected in the melon seed oil. SC-CO2 extractions were performed in a range of 30-55 degrees C, 150-240 bar, 7-15 g CO2/min, 0.4-1.7 mm (mean particle size of the seeds) and 1-4 h. The optimal quantities of extracted oil, beta-sitosterol and stigmasterol were 36.8 g/100 g seed, 304 mg/kg seed and 121 mg/kg seed, respectively, at 33 degrees C, 200 bar, 11 g CO2/min, 0.4 mm and 3 h.