Neurogenic autonomic dysfunction (NAD) and polyneuropathy occur in common conditions like diabetes and alcoholism. However, it can also be seen in rare diseases like in this case report of amyloid light-chain amyloidosis: primary amyloidosis. A 56-year-old man presented with polyneuropathy, a sympathetic dysfunction causing orthostatic intolerance, syncope, parasympathetic dysfunction and involvement of the enteric nervous system. The report illustrates, that routine screening can be insufficient in diagnosing amyloidosis. NAD and polyneuropathy without clear aetiology may require a multidisciplinary elucidation of more rare diseases.