Since progressive supranuclear palsy (PSP) was first reported as a separate clinicopathological entity in 1964, hundreds of other cases have been recorded, and PSP is now one of the most common atypical Parkinson-plus disorders. Diagnostic criteria have been developed by the National Institute of Neurological Disorders and Stroke and the Society for PSP, Inc. Because there is no biological marker for PSP, definitive diagnosis depends on neuropathological examination. Characteristics of PSP include gait disturbances, supranuclear ophthalmoplegia, axial limb rigidity, and frontal lobe dysfunction. Although there are no treatments that alter the natural history of disease in PSP and no drugs that provide significant symptomatic benefits, several supportive measures are available.