Abstract: Chemical composition of the essential oils obtained of stems, leaves and flowers of the Prangos acaulis, at full flowering stage were isolated by hydrodistilation method and investigated by GC/MS. A total of 11 compounds constituting 100% of stems oil, eighteen compounds constituting 99.74% of leaves oil and 22 compounds constituting 98.18% of flowers oil have been identified and quantified. The major components of stems oil were 3-ethylidene-2-methyl-1-hexen-4-yne (56.8%) and α-pinene (34.2%). The major components of leaves oil were α-pinene (39.54%), 3-ethylidene-2-methyl-1-hexen-4-yne (37.94%) and α-terpinene (10.9%) and the major components of flowers oil were α-pinene (25.04%), 3-ethylidene-2-methyl-1-hexen-4-yne (23.51%), α-terpinene (17.26%) and limonene (13.64%).