Bronchial mucous plugging is the main precipitating factor of acute respiratory failure for patients with neuromuscular disease. Manually assisted coughing and mechanical insufflation-exsufflation can effectively eliminate airway secretions without resorting to tracheal intubation provided that bulbar muscle function is sufficient to permit assisted peak cough flows of 160 l/min or greater. We now report successful use of mechanical insufflation-exsufflation to prevent acute respiratory failure for a patient with amyotrophic lateral sclerosis with no measurable peak cough flow.