Fennel is a native plant of Mediterranean Flora, well known and used since antiquity. Because of its great industrial and commercial value, it is widely cultivated all over the Balkan area. Fennel is mainly used for its anethol content in local and national spirits beverages, as far as in pharmaceutical, cosmetics products, and in confectionery as well. The essential oil of several fennel commercial samples (Foeniculum vulgare Mill.) from three Balkan countries (Bulgaria, Greece, and Turkey) were studied, considering the yield and the quality of the obtained essential oils. The obtained yields of the essential oils ranged among 1.8-5.5%, whereas the anethol percentage varied from 65% up to 83%. The qualitative analysis of the oils was determined by GC/MS.