nrDNA ITS sequence variation of Ferula species were studied by comparing with the other species of Ferula, Leutea and Dorema to clarify relationships amongst the taxa and infrageneric delimitation of the genus Ferula. In total, 35 nrDNA ITS sequence accessions (34 species) of Ferula, Leutea and Dorema were included in the analyses. 10 of these accessions were newly sequenced and belonged to Turkish species. Possible phylogenetic relationships amongst the species were determined using Maximum parsimony and neighbour joining tree methods. The analyses showed that the genus might be monophyletic upon the addition of Leutea and Dorema, but did not support the classification of the genus dividing into the subgenera.