Three studies were conducted to describe the flowering and fruit set, pollination ecology and genetic relationships and variations of Jatropha curcas L. accessions in Malaysia. For the first study, investigations were carried out by observing the floral morphology, flowering sequence of pistillates, floral anthesis time, flower daily anthesis, flowering and fruiting behaviour pattern, flower sex and fruit set ratio of J.curcas. The organogenesis of the floral reproductive organs was examined using Scanning Electron Microscope. For the second study, investigation was carried out by observing the flower visitors behaviour based on the duration of each visit by an insect species, mean abundance, peak hour of visitation, and rate of visitation during 5 min periods (number of visits/min) throughout the day for 10 plants. 8 insect species were found to visit J.curcas flowers. For the third study, the experiment was undertaken to assess the extent of genetic diversity in a representative set of 16 accessions of J.curcas. ISSR analysis was used to establish the genetic relationship among the accessions. Only 6 ISSR primers generated a polymorphic banding profile out of 8 primers used.