Hydrodistillation of dried leaves of selected olive varieties harvested in half-ripe fruit phase was performed in a Clevenger apparatus (for two hours and 30 minutes) in the laboratory of the Institute for Adriatic Crops and Karst from October 19 to October 28. The essential oils obtained by the hydrodistillation process were dried with anhydrous sodium sulfate. Samples of essential oils prepared in this way are stored in glass bottles at a temperature of 4°C. These essential oils will determine the profile of volatile substances, which could be responsible for attracting the olive fruit fly (Bactrocera oleae Rossi).