In this study, compositional analysis of the sterol fraction and triterpenic alcohols of olive oil was made assess the degree of purity of the oil and the absence of admixture with other plant oils. This determination also permited characterization of the type of olive oil. In the present work, 30 samples of olive oil supplied from the markets of Adana, Osmaniye and Mersin in 2015 and 2016 were analyzed, and the validation studies were carried out in the analysis method used. The sterol fractions were separated from the unsaponifiable fraction by silica gel plate chromatography, and later they were analyzed as the trimethylsilyl ether derivatives by capillary column gas chromatography. The validation results obtained were evalu- ated in accordance with TGK-Olive Oil and Pirina Oil Communiqué (Communiqué No: 2010-35).