abstract essential oil from the rhizomes of zingiber neesanum (graham) ramamoorthy from the western ghats region of southern india was isolated and characterized by gc and gc-ms. oil constituents were identified by comparison of individual mass spectra with databases and the literature, linear retention indices and co-injection. sixty-one constituents, comprising 97.4% of the oil, were identified. phenylbutanoids, viz. ( e )-1-(3',4'-dimethoxyphenyl)butadiene (31.1%), a potential antiinflammatory compound, and ( e )-1-(3',4'-dimethoxyphenyl)but-1-ene (23.1%) were isolated from the oil by prep. tlc, characterized by ir, uv, 1h-nmr and ms and quantified by external standardization. ( e )- - ocimene (12.7%), - pinene (7.4%) and linalool (4.0%) were the major terpenoid constituents in z. neesanum rhizome oil. copyright (c) 2007 john wiley & sons, ltd.