In this work, optimization of supercritical methanol extraction and transesterification for the production of biodiesel was investigated using Jatropha curcas L. seeds. Several important process parameters including heat pretreatment (45°C-105°C), particle size (0.5 mm-2.0 mm), temperature (200°C-300°C), reaction time (10 min-120 min), solvent to solid ratio (SSR) (5.0-20.0 ml/g) and co-solvent to solid ratio (CSR) (0-5.0 ml/g) were being studied by varying one factor at a time. The experiment was carried out in a high pressure batch reactor and supercritical methanol served both as the oil-extraction solvent as well as esterification/transesterification reagent which proceed simultaneously in the reactor. Co-solvent was required to accelerate the initial oil extraction phase to improve the overall kinetic of the reaction. Fatty acid methyl ester (FAME) or biodiesel yield was calculated in relation to the total extracted oil obtained from n-hexane Soxhlet extraction for 24 hours. The highest efficiency for the process to obtain the highest biodiesel yield was at 103.5% with the following optimized conditions: 105°C heat pretreatment, ≤1.0 mm particle size, 300°C temperature, 60 min reaction time, 10.0 ml/g solvent to solid ratio and 2.5 ml/g co-solvent to solid ratio. Optimization of the process was important in order to compare the process intensity with other biodiesel production method to produce high amount of biodiesel. The results from this experimental work proved that the above catalyst-free biodiesel production method had high potential to be further investigated for commercialization.