Fungi are ubiquitous in nature spreading across large geographic regions at any given timeframe. Non seasonal predisposition of fungi makes it convenient for them to cause rampant infections throughout the year. Moreover, wide range of incubating temperatures for their growth makes them resistant to adverse climatic conditions. Most commonly occurring environmental molds belong to the Aspergillus species which can cause variety of infections in humans ranging from simple colonization to more invasive pulmonary aspergillosis. Predisposition of Aspergillus in the respiratory tract is due to the common mode of transmission by inhalation of spores. Immune compromised and chronically infected patients are susceptible to invasive pulmonary aspergillosis which has significant morbidity and mortality. Knowledge on pathogenesis, distinct clinical and radiological features in various groups of individuals would be useful in early recognition and management of various spectrum of infection caused by aspergillosis.