The effects of free fatty acid (FFA) and moisture contents in palm oil, as well as working volume ratio on the production of biodiesel (fatty acid methyl esters; FAMEs), were investigated using palm oil and a non-catalytic supercritical process. FAME content obtained using anhydrous palm oil was 95.8% during the non-catalytic supercritical process. FAME content produced with 15% moisture content and 15% FFA content was 94.4% and 95.1% respectively, which was similar to that of anhydrous palm oil with no FFA. The non-catalytic supercritical process was not affected by FFA or moisture content in oil. By increasing working volume ratio, reaction temperature decreased from 340 oC to 260 oC at the same pressure, whereas FAME content increased from 69.9% to 95.5%.