Abstract Distillation of the fresh fowering tops of Chaerophyllum prescottii DC collected from Altai region of Siberia yielded 0.22% mobile colorless oil. Analysis of the oil by GC, GC/MS for the frst time has revealed the presence of 18 substances with the major components consisting of (E)-Î²-ocimene (35.6%), (Z)-Î²-ocimene (19.4%), Î³-terpinene (18.8%), myrcene (10.6%) and terpinolene (4.6%), representing 89.0% of the total oil, while 11.0% of the oil comprised other minor components.