We report a case of an 85-year-old woman who presented with acute respiratory failure, caused by aspirating a sucralfate tablet that totally occluded her left main-stem bronchus. Acute respiratory failure resolved after bronchoscopic removal of the markedly expanded tablet. To our knowledge, the acute obstruction of a main-stem bronchus by an aspirated foreign body has not been previously described in adults. We believe that the unusual properties of sucralfate tablets (rapid expansion and mucosal binding) were contributing factors in this patient.