Jatropha curcas is a plant that accumulates high-quality oil in its seeds, which is capable of being transformed into liquid biofuel. However, several aspects of its fl owering are still unknown, which is a key step in the production of fruits, seeds, and oil. Flowering is a complex process that is regulated by various factors at the molecular level, including microRNAs (miRNAs). Th ere is evidence suggesting that the miRNAs of the miR156 and miR172 families play a key role in the fl owering transition of plants. For this reason, the dynamics of miR156 and miR172 were studied during a production cycle of J. curcas. Our results reveal that J. curcas has a mechanism for the expression of these miRNAs that diff ers from that reported for the vast majority of angiosperms, since the expression of both families of miRNAs was positively correlated with the phenological state of J. curcas. We discuss the implications of these fi ndings and how the regulatory mechanisms of miR156 and miR172 diff er from what has been reported thus far.