A battery of cardiovascular reflex tests were performed in twenty patients with chronic renal failure on intermittent haemodialysis. Using age-adjusted confidence limits, old-aged uraemics showed more extensive parasympathetic and sympathetic dysfunction than middle-aged patients. The results suggest that autonomic nervous system in the elderly is more susceptible to uraemic toxins than in the middle age. This should lead to better preventive and therapeutic strategies in older uraemics.