Aim: Electrophysiological monitoring of the activity of the penile sympathetic skin responses (PSSR) in healthy menand patients with erectile dysfunction (ED). Methods: PSSR were recorded from the skin of penis with disk elec-trodes at the time of electric stimulation of left median nerves. Results: PSSR were recorded from all the healthymen and almost all the patients. In healthy men the latency of P_0, the latency of N_1, the duration of N_1 and the ampli-tude of N_1 were 1249 ± 111 ms, 2239 ± 286 ms, 1832 ± 505 ms and 470 μV (median), respectively. In ED patientsthe latency of P_0, the latency of N_1, the duration of N_1 and the amplitude of N_1 were 1467 ± 183 ms ( P < 0.01), 2561± 453 ms (P < 0.05), 2560 ± 861 ms (P < 0.01 ) and 91 μV (P < 0.01), respectively. The normal latency of Powas less than 1471 ms. The normal amplitude of N1 was more than 235μV. According to this normal value, of 20 pa-tients 11 showed longer latency of P_0, and 14 showed lower amplitude of N_1 as compared with tho Aim: Electrophysiological monitoring of the activity of the penile sympathetic skin responses (PSSR) in healthy men and patients with erectile dysfunction (ED). Methods: PSSR were recorded from the skin of penis with disk elec-trodes at the time of electric stimulation of left median nerves. Results: PSSR were recorded from all the healthymen and almost all the patients. In healthy men the latency of P_0, the latency of N_1, the duration of N_1 and the ampli-tude of N_1 were 1249 ± 111 ms, 2239 ± 286 ms, 1832 ± 505 ms and 470 μV (median), respectively. In ED patient latency of P_0, the latency of N_1, the duration of N_1 and the amplitude of N_1 were 1467 ± 183 ms (P <0.01), 2561 ± The normal amplitude of Powas less than 1471 ms. The normal amplitude of N1 was more than 235 μV. According to this normal value, of 20 pa-tients 11 showed longer latency of P_0, and 14 showed lower amplitude of N_1 as compared with tho