Jatropha curcas (Euphorbiaceaefamily) is a multipurpose plant with considerable potential in biodiesel production, and in cosmetic and medicinal uses. The part of J. curcas usually used is the oil obtained from its seeds, whereas the leaves generally represent the waste material. The aim of this study was to characterize the composition and to preliminary investigate the biological activity ofJ. curcas leaves obtained from plants by a breeding program. To describe genomic structure, molecular markers were applied. For biological study, two genotypes (JA and JB) that are genetically divergent were selected by cluster analysis. A phytochemical analysis was carried out to characterize the chemical composition of the extracts, which resulted rich in biologically active compounds, whereas toxic phorbol esters were absent. Biological assays showed an antiproliferative effect on the Buffalo normal rat liver cell line (BRL-3A), with genotype B being more potent than that of the counterpart (JA).The purified compounds isolated did not show antiproliferative activity, suggesting that the effect observed was due to the phytocomplex and should involve several secondary metabolites. This study highlights that a plant of the same genus and same species that has been cultivated in the same soil and climatic conditions can be characterized by a high variability. This is what makes research in pharmacognosya complex process.