Background/Aims: There is little published data regarding autonomic symptoms in dementia. This study aimed to examine the prevalence and severity of autonomic symptoms in patients with different subtypes of dementia in comparison with healthy controls, and their association with levels of physical activity, depression, quality of life and ability to carry out activities of daily living. Methods: Prevalence and severity of autonomic symptoms in Parkinson’s disease dementia (PDD, n = 46), dementia with Lewy bodies (DLB, n = 32), vascular dementia (VAD, n = 38), Alzheimer’s disease (AD, n = 40) and healthy controls (n = 42) were assessed using a structured symptom scale. The associations between autonomic symptoms and physical activity, Bristol Activities of Daily Living Score, Geriatric and Cornell Depression Scores and quality of life (Medical Outcomes Study 36-Item Short Form Health Survey, SF-36) were examined by multiple linear regressions. Results: Total autonomic symptom scores, urinary symptoms, constipation and postural dizziness were significantly higher in PDD, DLB and VAD patients than either controls or AD patients (all p < 0.05). Higher autonomic symptom scores were associated with poorer outcomes in all measures of physical activity, activities of daily living, depression and quality of life. Conclusion: The burden of autonomic symptoms is high in non-Alzheimer’s dementias. The identification of such symptoms is of importance because of the detrimental effect of these symptoms upon physical activity, depression, activities of daily living and quality of life.