Autonomic nervous function was investigated in 18 Gilles de la Tourette (GTS) patients and in 23 controls, who matched the patients in age, sex, baseline blood pressure and baseline heart rate. Four heart rate tests were used (variation at rest, during deep breathing, following standing up and during a Valsalva manoeuvre), and two blood pressure tests (standing up and sustained handgrip). The only significant difference between the groups was found in the Valsalva test. This was due to the initial heart rate increase which was higher in the GTS group; the subsequent decrease did not differ between the groups. Increased sympathetic activity is a possible explanation for this finding, but no additional evidence in its favour was found. No signs of autonomic failure were found.