Progressive supranuclear palsy (PSP) comprises psychiatric, neurological and physical complications. In the late stage, most patients with PSP are bed-bound because of motor disability. PSP manifests as predominantly axial abnormality in posture and abnormal muscle tone, resulting in cervical retroflexion and somatic pains. Severe retroflexion of the neck is frequently a cause of repeated aspiration pneumonia that affects survival expectancy. We injected botulinum toxin (BTX) for severe retroflexion using a CT-guided procedure to confirm the anatomical locations of paravertebral muscles and to localize the paravertebral target muscles for a patient with PSP who had repeated pneumonia caused by retroflexion-related dysphagia. BTX injection treatment markedly ameliorated the cervical dystonia and concomitant dysphagia. The patient has recovered and may be able to be discharged to home. There are few reports on the BTX injection technique, but BTX has analgesic effects and induces relaxation of abnormal muscle tension. Therefore, it may be applicable to other movement disorders at the late stage.