Alteration of autonomic function is considered to be associated with idiopathic Parkinson's disease. Previous studies have reported conflicting results about cardiovascular autonomic dysfunction in these patients. We studied cardiovascular reflex (lying to standing, deep breathing, postural blood pressure and Valsalva ratio) in 44 patients with idiopathic Parkinson's disease (according to Ewing et al., 1981) and spectral analysis of heart rate variability in 15. Thirty age matched subjects served as controls. Fifty-six of the PD patients had normal cardiovascular reflexes, 35% had one or more borderline tests, while only 11% had at least one pathological result. No significant differences were detectable for cardiovascular reflexes in the PD population as compared to normal controls. Within the PD group multivariate analyses including age, disease duration, treatment and motor impairment were significant for disease duration (lying to standing, P = 0.05) and dopaminergic treatment (postural blood pressure, P = 0.05). Spectral analysis of heart rate variability showed in the PD population a decrease of the 2 main components LF and HF, due mainly to heart rate variability decline with age.