Post nasal drip (PND) and catarrh were among the diseases much dealt with in Iranian traditional medicine. Traditionally, it included a wide range of concepts. The purpose of this review was to provide a brief overview of the opinions of Jorjani, Avicenna and Rhazes on PND and catarrh and to compare them with the findings in modern medicine. PND and catarrh are roughly and not exactly equivalent to Zokam and Nozleh in Persian traditional medicine. What is common between traditional and the modern medicine is that both believe that these diseases are rooted in brain. It seems that things like cold, rhinitis, sinusitis, pharyngeal secretions and their side effects are closely related to the catarrh and PND. This study was a retrospective study which examined the ideas of Iranian scholars like Jorjani, Avicenna and Rhazes on identifying and treating catarrh and PND and compared them with modern medical science. In this study on traditional medical texts, it was found that the diagnosis, prevention and recommendations on PND and catarrh in both modern and Islamic traditional schools of medicine are much the same in such a way that even the examining tools were similar.