To our knowledge, there has not previously been a case report of autoimmune autonomic ganglionopathy (AAG) presenting with ‘orthostatic vomiting’, however in our patient, this was a significant feature. A 53 year old male presented with an acute history of forceful, orthostatic vomiting with back pain. Further symptoms included diaphoresis, dry mouth and urinary retention. Past medical history includes migraines with aura, essential tremor, and ulcerative colitis. Pupils were slowly reactive to light, though neurological examination was otherwise unremarkable. Routine blood tests and neuroimaging were unremarkable. CSF analysis revealed elevated protein. Ganglionic acetylcholine receptor antibodies were strongly positive. With high dose corticosteroids there was dramatic resolution of symptoms. In health, standing leads to autonomically mediated splanchnic vasoconstriction improving cardiac preload by diverting blood back to the systemic circulation. In AAG, ganglionic nAChR synaptic transmission is disrupted. Aberrant autonomic reflexes in response to postural drops in blood pressure may lead to inadvertent effects on GI smooth muscles, manifested as GI dysmotility, nausea and vomiting. Indirect evidence of this link comes from studies in other dysautonomic conditions such as postural orthostatic tachycardia syndrome (POTS).