Respiratory depression and alveolar hypoventilation require establishment of an airway and mechanically assisted ventilation. A selective respiratory stimulant, vanillic acid diethylamide, produced effective increases of ventilation in 95 of 119 patients with various types of hypoventilatory states. The depth of respiration was increased. The rate was increased also, but to a lesser extent. Prolonged respiratory stimulation was achieved by continuous intravenous therapy in cases of acute depression and by oral administration in convalescent or chronic hypoventilatory states, particularly where aggravated by sleep or by oxygen therapy. This agent was found to be a most valuable adjunct to the management of the patient with severe chronic pulmonary disease and depressed respiration. Side effects were minimal with a wide margin of therapeutic safety demonstrated.