The objective of this study was to assess sympathetic activity within the hand in patients with unilateral carpal tunnel syndrome. In 53 patients, 42 female (79%) and 11 male (21%), having a mean age of 56 years, with clinically and electrophysiologically confirmed unilateral CTS, the sympathetic skin response (SSR) and capillaroscopy examination of the nail folds was obtained for the affected and unaffected hand. Mean values of the SSR parameters did not differ statistically significantly between affected and unaffected hands. Qualitative analysis of the SSR graphs revealed no response in one patient (2%), reduced SSR in seven (13%) and normal SSR in 45 patients (85%). Capillaroscopy showed that the mean diameters of afferent and efferent capillary vessels were not statistically significantly different in the affected and unaffected hand. The results obtained in our study indicate a slight but statistically insignificant effect of the compression of the median nerve on the activity of the sympathetic nervous system in the distribution of this nerve.