Juvenile hormone III (JH III) is one of the five closely related sesquiterpenoid compounds important in the regulation of an insect physiological processes in both the developing and the mature insect. JH III and its biosynthetic intermediates, farnesol and methyl farnesoate were detected in the in vitro Cyperus aromaticus plantlets and the mature plants growing in the field. A higher amount of methyl farnesoate (52.7%) and farnesol (31.4%) were found to be present in the in vitro plantlets as compared to the field grown mother plants which contained lower methyl farnesoate (19.5%) and farnesol (14.8%). On the other hand, the mature mother plant (4 months old) contained a higher percentage of JH III than the in vitro plantlets. The estimated content of JHIII analyzed by gas chromatography indicated that the amount of JHIII in the 10 weeks old in vitro plantlets and the four months old mature plants of C. aromaticus was 0.076 $mu extrm{g}$/g and 0.085 $mu extrm{g}$/g respectively. This study indicated that in vitro culture system could be a potential tool for the production of this natural derived bio-insecticide and could provide a material source for further investigations of the biosynthesis of JH III in C. aromaticus.