Hydrodistillation of dried leaves of selected olive varieties was performed in a Clevenger apparatus (for two hours and 30 minutes) in the laboratory of the Institute for Adriatic Crops and Karst from September 1 to September 4. 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).