Background: Essential oils are fragrances extracted from plants. They have a smooth consistency and pleasant smell. Essential oils have been applied in aromatherapy, cosmetics, food and pharmaceutical products. The aim of the study was to analyze the composition of selected essential oils used in respiratory diseases. Material and Methods: The qualitative analysis was performed by gas chromatography with mass spectrometry. For the study 6 essential oils available in Polish shops and used in various respiratory diseases were chosen. The results were compared with the information provided by the manufacturer and the literature. Results: The method used in the presented work allowed to qualitatively identify the main components in studied essential oils. In the analyzed samples generally occurred: α- i β-pinene, limonene, terpinen-4-ol and caryophyllene. In addition to limonene, the presence of linalool, eugonol and geraniol, potentially allergenic substances, were also detected. Conclusions: The qualitative composition of the studied essential oils comply with the existing literature data. Their main ingredients show antimicrobial and antiviral activities, therefore they are used to eradicate the symptoms of infection. However, the attention should be paid to the composition of the products because they often comprise potential allergens. Information on the presence of such a substance in the preparation should be clearly marked by the manufacturer on the packaging. Fragrances are also found in a number of household products that increase their concentration in the air of living premises, thereby increasing the risk of side effects especially in people with allergies or sensitive. Med Pr 2018;69(2):167–178