Background: Asthma is a long-lasting inflammatory illness manifested as airway hyper-responsiveness induced by a series of inflammatory processes in the respiratory tract that can cause severe signs of an asthmatic attack. Periostin seems to subsidize numerous pathologic pathways in bronchial asthma, such as subepithelial fibrosis, eosinophil accumulations, and mucus overproduction from the goblet cells. This study intended to assess the plasma levels of periostin in bronchial asthma and its association with asthma severity