In this work two genus of the Jatropha family: the Jatropha gossypiifolia (JG) and Jatropha curcas L. (JC) were studied in order to delimitate their potential as raw material for biodiesel production. The oil content in wild seeds and some physical-chemical properties of the oils and the biodiesel obtained from them were evaluated. The studied physical-chemical properties of the JC and JG biodiesel are in acceptable range for use as biodiesel in diesel engines, showing a promising economic exploitation of these raw materials in semi-arid regions. However, further agronomic studies are needed in order to improve the seed production and the crude oil properties. (C) 2008 Elsevier Ltd. All rights reserved.