1,8-cineole (eucalyptol) in a therapy of respiratory diseases 1,8-cineole (eucalyptol) is a natural terpenic compound isolated from eucalyptus essential oil, it is present also in other plant species, especially from Lamiaceae, Myrtaceae, and Zingiberaceae family. Plants containing 1,8-cineole have long been used to treat common cold and other respiratory diseases, gastrointestinal complaints, fever, infections, asthma, rheumatism, and skin conditions. 1,8-cineole is used in foods, cosmetics, perfumery, and also in pharmaceutical industry. 1,8-cineole exerts an antimicrobial, antiviral, mucolytic, anti-inflammatory and bronchodilatory effect and is suitable for the treatment of respiratory infections and other diseases. Medicinal effects were confirmed not only in vitro and in animal studies, but also in clinical trials. Medicinal products and dietary supplements containing 1,8-cineole are available.