This article presents selected text on respiratory medicine from the famous book of medicine, Al-Qanun fi al-Tibb (the Canon of Medicine) by Avicenna (981-1037 AD), which was taught for 600 years as a standard text of medicine across medieval Europe. The authentic manuscript of the Canon of Medicine is located in the Central Library of the Tehran University of Medical Sciences, and the section on respiratory diseases was studied for the most relevant information - information that would be informative and interesting for present day physicians and pulmonologists. The results of the analysis are presented in the article. Respiratory diseases are discussed in depth in volume 3 of the Canon of Medicine. Avicenna discusses in detail the functional anatomy and physiopathology of the pulmonary diseases that were known in his time. He also describes the signs and symptoms of various respiratory diseases and conditions in the five chapters of volume 3 (breathing, voice, cough and hemoptysis, internal wounds and inflammations and principles of treatments) that are remarkably similar to those of modern pulmonary medicine. In addition, the herbal and nonherbal treatment of respiratory diseases and their signs and symptoms, mentioned in volume 2 of the Canon of Medicine, is also presented. In the time of Avicenna, the presentation of respiratory diseases, their treatment and their prognosis was much different than in modern times. There was more reliance on history, physical examination (which was mostly based on visual observation), individual variation, environmental factors, diet, and so on, for diagnosis and treatment. Nevertheless, going through a popular historic text such as the Canon of Medicine adds to our knowledge of the developments in the area of respiratory medicine at the time of Avicenna.