Two patients, a 28‐year‐old male and a 70‐year‐old female, with chronic insulin dependent diabetes mellitus and evidence of autonomic neuropathy were studied using cortical evoked responses following esophageal balloon and electrical stimulation. Both patients had symptomatic gastroparesis, poor gastric emptying, and reduced gasfroduodenal motility including abnormal results of scintigraphy and manome‐try. There was slowing of afferent vagal conduction but good evoked potential responses were recorded even though one patient could not feel electrical stimulation of either the proximal or distal esophagus. It is improbable that the gastric symptoms are due to an afferent autonomic neuropathy, but symptoms may well be related to impairment of motor vagal pathways. Nevertheless, afferent vagal pathways are involved in severe diabetes mellitus. The clinical significance of this delay in conduction velocity of afferent pathways remains to be established.