Respiratory sequelae occurring in the victims of the Bhopal, India disaster were summarized. Clinical, radiological, and physiological abnormalities that developed in 978 persons, 520 females, admitted to Gandhi Medical College, Bhopal after the methyl-isocyanate (624839) leak at the Union Carbide factory were described. A total of 733 patients lived within 1 kilometer (km) of the factory, 127 within 1 to 2km, and the rest more than 2km from the facility. A total of 544 patients had symptoms such as breathlessness, cough, presence of pink froth, throat irritation, a choking sensation, chest pain, hemoptysis, and hoarseness. Most of the patients had tachycardia, tachypnea, and ronchi and crepitations. Most of the symptoms decreased over time; however, a few persons developed severe paroxysmal dyspnea that persisted for at least 6 months. Most patients had abnormal chest X-rays that contained diffuse nonhomogeneous opacities, mostly in the mid and lower zones. The opacities began clearing after the first month post exposure. Spirometric evaluations of 224 patients revealed that 36 had significantly decreased forced vital capacity and 1 second forced expiratory volume values and 62 had evidence of airway obstruction or restriction. Blood gas analyses showed slight hypocapnia and significant carboxyhemoglobinemia and methemoglobinemia. Bronchoalveolar lavage performed in eight subjects produced infiltrates indicative of tracheobronchial mucosal swelling. Lung biopsies performed on three subjects showed typical symptoms of bronchiolitis obliterans, a characteristic feature of toxic gas inhalation. Patients who were treated with methyl-prednisolone showed a good response.