Inhaled substances may cause injury in pulmonary epithelium at various levels of respiratory tract, leading from simple symptoms to severe disease. Acute inhalation injury (AII) is not uncommon condition. There are certain high risk groups but AII may occur at various places including home or workplace. Environmental exposure is also possible. In addition to individual susceptibility, the characteristics of inhaled substances such as water solubility, size of substances and chemical properties may affect disease severity as well as its location. Although AII cases may recover in a few days but AII may cause long-term complications, even death. We aimed to discuss the effects of short-term exposures (minutes to hours) to toxic substances on the lungs.