Autonomic dysfunction is a common complication of peripheral neuropathies. It is often of little clinical importance, but some conditions may cause profound disturbance of autonomic function, including postural hypotension, impotence and impairment of heart rate and bladder and bowel control. Autonomic function can be evaluated by a number of investigations, some of which can be performed in a neurophysiology laboratory. Diseases that primarily affect small nerve fibres or cause acute demyelination of small myelinated fibres are most likely to cause autonomic dysfunction. Management includes treating the underlying cause and symptomatic therapy.