We prospectively performed neurophysiologic studies in nine Fabry's Disease (FD) patients (8 male and 1 female) in order to describe the results of nerve conduction studies (NCS) and electromyography (EMG) and to verify whether the sympathetic skin response (SSR) is impaired in these patients. The investigation protocol included SSR, sensory and motor NCS and EMG. SSR was performed not only in FD patients, but also in 18 normal controls. All FD patients had normal nerve conduction studies and electromyography. SSR was present in all controls with a mean amplitude of 1453.6+/-682.3 microV. However, the SSR was absent in six and lower than 500 microV in the remaining FD patients. All patients had normal sensory and motor NCS and EMG. SSR, on the other hand, was significantly altered in all patients and this test could, therefore, be useful in the diagnostic evaluation of FD patients.