The water-distilled oil from the aerial parts of Peucedanum, cervariifolium of Iranian origin was analyzed by a combination of GC and GC/MS. Twenty-eight components were identified, which approximately constituted 93.3 % of the oil. The major constituents of the oil were alpha-guaiene (11.9 %), gamma-muurolene (7.4 %), viridiflorene (10.9 %), alpha-selinene (16.3 %) and beta-selinene (27.4 %).