This chapter describes autonomic dysfunction in Parkinson’s disease and Parkinsonism. Autonomic dysfunctions in Parkinson’s disease are cardiovascular dysfunction, bowel dysfunction, lower urinary tract dysfunction, and sexual dysfunction briefly explained along with their prevalence, etiopathogenesis, and treatment. Cardiovascular autonomic dysfunction in Parkinson’s disease and related disorders includes orthostatic hypotension (OH), supine hypertension, and postprandial hypotension. Orthostatic hypotension is associated with increased rate of morbidity and mortality. Autonomic dysfunction affecting the gastrointestinal (GI) tract is common in Parkinson’s disease and MSA and can lead to slow colonic transit and delayed gastric emptying. Lower urinary tract symptoms (LUTS) can arise from storage dysfunction (an overactive bladder, symptoms of urinary urgency, frequency, incontinence, and nocturia) and/or of voiding dysfunction (obstructive symptoms, e.g., hesitancy and poor flow).