The sterol profile of three Algerian virgin olive oils produced from Guasto, Blanquette and Rougette cultivar’s, varieties grown in the East of the country, was established by gas chromatography using a flame ionization detector and coupled to mass spectrometry. Four sterol compounds were identified and characterized in the three oils which are, sitosterol always predominant (43-66%), delta 5-avenastérol (8-13%), stigmasterol (≤ 1,5%) and campesterol (1-2%) ; one methyl sterol (4-methylsterol) : citrostadienol (4-7%) and two triterpenic alcohols : 24-methylene cycloartanol (10-33%) and cycloartenol (3-13%). These results vary according to campany and variety. Our study shows that most of these compounds were affected by climatic conditions especially during the campanies 2004-2005 and 2005-2006. The amounts of the four identified sterols are in agreement with the European regulation (Reg. (EEC) n°2568/91, appendix 1).