In December 1986 a 30-month-old female child with morbid obesity and respiratory failure was admitted to the Izaak Walton Killam Hospital for Children in Halifax. The etiology of the obesity was found to be dietary in origin after ruling out genetic, neurological and metabolic causes. This patient exhibited somnolence and cyanosis in association with hypercapnia and right ventricular overload. Her respiratory failure in the presence of a normal upper airway required ventilatory support, first with nasal endotracheal intubation, and then, tracheotomy. Weight reduction normalized her capillary blood gases and her somnolence disappeared. Subglottic stenosis hampered removal of the tracheotomy tube until 9 months after admission. The pathogenesis and management of obese hypoventilation syndrome are reviewed by the authors.