Jatropha or physic nut (Jatropha curcas) is being genetically improved in many countries for commercial plantation as a source of biodiesel. This study investigates the variation in physicochemical properties of seed and oil obtained from F2 plants of a cross between J. curcas cv."Chai Nat" and J. integerrima (a local dwarf ornamental type from Thailand). The results revealed a high diversity in properties of seed and oil showing a number of promising genotypes. Out of 296 F2 plants derived from an F1 plant, 42 of them showed small canopy size, high in seed yield, oil content, and oleic acid content, but low in linoleic acid content. Some plants showed a kernel to seed weight ratio of more than 0.8. Some plants had over 40% seed oil content. Phorbol ester content of their seeds varied from 0.7–4.6 mg/g, with an average of 1.9 mg/g. Seed yield of the F2 plants showed a positive correlation with oil yield per plant (r=0.99), while there were weak relationships between oil content with the other traits. A highly negative correlation was observed between oleic and linoleic acids (r=-0.97).