The performance of oil expression from Jatropha curcas L. (Jatropha) seeds using a pilot scale continuous screw press was studied. The influence of seed pre-treatment, i.e. whole, crushed and deshelled seeds, screw-press operational settings (shaft rotational speed and press cake outlet section) was investigated. For each experiment, the material flows (seeds, press cake and crude oil) were measured and analysed for their oil, water and solids contents. The behaviour of oil expression was very sensitive to seeds preparation. It was shown that for whole seeds, a good reproducibility was obtained, whereas for crushed or deshelled seeds, heterogeneity of the feed led to unsteady pressing conditions and important discrepancies in the performance. The presence of seed shells contributes to build a porous solid matrix which favours oil flow through the press cake. For whole seeds, a correlation between oil recovery and seed throughput was proposed. The mass balance consistency was carefully analysed and oil yield was determined using a direct and an indirect method. A good linear correlation between seed and press cake throughputs was observed: the seed throughput is always divided in a stream of crude oil and a stream of press cake in the same proportion. This important result shows that the residual oil in press cake and the amount of solids carried by the oil are directly related and determine the efficacy of the separation. Thus, for a given screw press and feed material, the oil sediment content can be predicted knowing the oil recovery. The energy consumption during pressing was measured and modelled as a function of oil recovery and seeds oil content. The specific mechanical energy for oil expression was less than 5% of the energy content of the oil and a minimum mechanical energy requirement was generally observed at oil recoveries between 70% and 80%.