A 74-year-old man was found to have a paralysed left hemidiaphragm within four months of the appearance of a typical herpes zoster rash involving his left shoulder and neck. Investigations, including bronchoscopy and computed tomography of the chest, failed to detect a cause for the diaphragmatic paralysis. We believe that the cervical zoster and diaphragmatic paralysis were causally related, a rare but recognised association.