Under normothermic conditions, skin vascular conductance in humans is unchanged at the onset of voluntary isometric exercise despite significant increases in skin sympathetic nerve activity (Ray & Wilson, 2004), except when exercise intensity is relatively high (Cotzias & Marshall, 1992). One study, however, reported that skin blood flow increased in the non-active arm during muscle contractions elicited by contralateral neuromuscular electrical stimulation (Rendell et al. 1997). This could occur through afferent-mediated antidromic vasodilation (Wu et al. 2006). We investigated whether two types of stimulation (low frequency, isometric tetanic) that are typically used for calf muscle treatment would induce changes in skin vascular conductance at different sites on the body. With ethical approval, twenty healthy subjects, 11 male, 9 female, (age 20.4 ± 0.4 yrs, body mass index 23.2 ± 2.8, means ± SD) participated in three calf exercise protocols whilst seated (room temperature 21 ± 0.1 oC):- voluntary plantarflexion contraction at 30% maximal (Vol, 2 mins), electrically evoked (20 Hz) plantarflexion contraction at 30% maximal (Stim, 2 mins), and low frequency (8 Hz) at maximum tolerated intensity (8 mA, 5 mins). Exercise was performed by one leg while skin perfusion was measured by Laser Doppler flowmetry from forehead, forearm, shin and toe on the contralateral side. Mean arterial pressure (MAP) was used to calculated skin vascular conductance changes from baseline during exercise. Skin electrodermal activity was monitored as galvanic response (GR) from electrodes on the fingers. Resting MAPs and heart rates were 87 ± 2 mmHg and 67 ± 3 bpm (mean ± S.E.M.). Stim exercise elicited significant increases (P<0.05 v. baseline) in MAP (5 ± 2 mmHg) and GR (2.2 ± 0.6 μS) but not heart rate. Skin conductance did not change significantly at forehead or forearm but increased by 95 ± 36 % at the shin (P<0.05) and 152 ± 34 % at the toe (NS). Low frequency stimulation did not alter MAP, heart rate or GR but increased conductance at the forehead (58 ± 13 %, P<0.05), shin (130 ± 45 %, P<0.05) and toe (236 ± 74 %, P=0.07). Vol exercise increased MAP (8 ± 2 mmHg) and heart rate (5 ± 1 bpm) but not GR and the only site to show a significant increase in conductance was the forehead (33 ± 9 % increase, P<0.05). Increases in skin vascular conductance during neuromuscular electrical stimulation suggest that, in comparison with voluntary exercise, afferent-mediated vasodilation may prevail during involuntary exercise in normothermic conditions whether there is evidence of sympathoexcitation (MAP or heart rate rise) or not. This could in part explain the beneficial effects of stimulation in patients with ischaemic limb disease (Debreceni et al. 1995).