Unani scholars have described certain diseases like Zeequn Nafas [Asthma] , Deedan-e-Ama [Intestinal Worms] , Daulfeel [Elephantiasis] , Nar-e-farsi [Eczema] and Jarb [Scabies] in their treatises, which are well known causes of eosinophilia. Moreover, there are some conditions namely Sual [cough] , Attas [Sneezing] , Hikka [Pruritus] , Hikkaul unf [Nasal itching] and Shara [Urticaria] , which reflect the concept of allergen in their etiology and management The invention of microscope played the vital role in the discovery of eosinophils. Thus, diseases which have been described since antiquity mimic with the eosinophilia, and a stepwise progression in knowledge has led to the present era as a well known clinical entity viz. Eosinophilia