The purpose of this study was to determine the effect of transcutaneous electrical nerve stimulation(TENS) on sympathetic tone in healthy subjects. Stimulation in the conventional and burst modes was applied to the skin of the forearm overlying the median nerve. TENS was applied for 20 minutes at an intensity sufficient to produce a perceptible though not uncomfortable sensation and no muscle contracion of the forearm musculature. The change in sympathetic tone was measured with skin temperature. Skin temperature was measured at the index finger and on the volar surface of the forearm in the stimulated limb. The conventional and burst modes did not change the skin temperature at any of the two measurement sites. We conclude that TENS, as applied in this study, does not influence sympathetic tone. Further research is needed to assess the sympathetic effects of TENS on patient groups, long term treatment and other modalities.