Allergic bronchopulmonary aspergillosis is primarily an immunologic disorder manifested by episodic bronchial obstruction (asthma or chronic obstructive pulmonary disease). The host response to local Aspergillus antigens gradually results in irreversible pulmonary injury. A high index of suspicion is required to make the diagnosis. Early and aggressive treatment is important in preventing the serious consequences of central bronchiectasis, pulmonary fibrosis and cor pulmonale.