Aspergillus pulmonary infection causes a spectrum of diverse diseases according to host immunity. The two major entities are invasive pulmonary aspergillosis and chronic pulmonary aspergillosis. The later can be divided into aspergilloma, then into chronic cavitary, more or less fibrosing aspergillosis, and finally into chronic necrotizing aspergillosis, or semiinvasive aspergillosis. The present article reviews this complex classification, which is necessary to reflect the diverse clinical aspect of the disease. Allergic broncho-pulmonary aspergillosis (ABPA), which is more a hypersensitivity reaction than an infectious process, will not be discussed here.