Some procedures, such as deep inspiration, increase sweat output (SSwR; sympathetic sweat response) and reduce cutaneous blood flow (SVR; skin vasomotor reflex) on the palm. We investigated SSwR, SVR, and cardiovascular function in 12 patients with progressive supranuclear palsy (PSP), 13 patients with Parkinson's disease (PD), and 9 healthy subjects. In the PSP patients, SSwR was severely diminished, whereas SVR was maintained and cardiovascular function was well preserved. In the PD patients, SSwR was relatively preserved, SVR was maintained, and some patients showed cardiovascular hypofunction. A combination of skin sympathetic and cardiovascular tests may be useful for distinguishing between PD and PSP.