abstract the composition of the laboratory-prepared turkish bitter orange oil (citrus aurantium l) samples (bitter orange fruits cultivated two different area) were studied. the volatile fraction was analyzed by gc and gc/ms, and 29 components were identified in the oil. the results obtained were compared with those in the literature for italian and spanish bitter orange oil. the identified components were grouped into six classes (monoterpene hydrocarbons, sesquiterpenes, oxygenated compounds, carbonyl compounds, alcohols, and esters). variations in the oil composition relative to the fruit provenance, the percentage of the each component and six classes, were also described. it was found that the oil composition varied according to the fruit provenance. the main components of the oil were limonene (93.68-94.32%), myrcene (1.73-1.86%), linalyl acetate (1.17-1.32%), linalool (0.33-0.46%), (-pinene (0.40-0.57%) and -pinene (0.39-0.45%).