We report a 59 year old woman who presented with double vision, nuchal pain and mild dementia. On neurological examination she demonstrated third, sixth and seventh nerve palsies and ataxia. Following intravenous ACTH and oral prednisone therapy she showed a remarkable recovery which left her with only a left facial weakness. She remained well for two years. She then developed bulbar palsy and profound dementia. Pathological examination revealed progressive supranuclear palsy (PSP). This patient demonstrated a greater variability in the course of PSP than has previously been recognized.