The symptoms caused by or relating to orthostatic hypotension (over 20 mmHg systolic blood pressure) were evaluated using a questionnaire in 72 patients with primary chronic autonomic failure, 32 of whom had pure autonomic failure (PAF, and 40 multiple system atrophy (MSA). The most common posturally related symptoms were dizziness (84% PAF, 83% MSA), syncope (91% PAF, 45% MSA), visual disturbances (75% PAF, 53% MSA) and suboccipital/paracervical 'coat-hanger' neck pain (8 l% PAF, 53% MSA). Chest pain occurred mainly in patients with PAF (44% PAF, 13% MSA). Improvement occurred with sitting or lying flat. Non-specific symptoms (weakness, lethargy and fatigue) were common in both groups (91% PAF, 85% MSA); six patients (one PAF, five MSA) had these symptoms only. Postural symptoms (mainly dizziness and neck pain) were worse in the morning and with warm temperature, straining, exertion, arm movements and food ingestion; they were more common in PAF. Compensatory autonomic symptoms, such as palpitations and sweating, did not occur in either group. In conclusion, orthostatic hypotension caused symptoms of cerebral hypoperfusion (syncope, dizziness and visual disturbances); neck pain, presumably due to muscle hypoperfusion, also occurred frequently. These symptoms were exacerbated by various factors in daily life and were relieved by returning to the horizontal. Non-specific symptoms (such as fatigue) also were common. In MSA, despite substantial orthostatic hypotension, fewer patients had syncope, visual disturbance and neck pain; the reasons for this are unclear. Lack of these features does not exclude the need to assess and investigate orthostatic hypotension and possible autonomic failure.