Twenty-four of 576 consecutive patients with spinal cord injuries developed acute gastroduodenal ulceration and hemorrhage. Twenty-two were males and two were females: 88% were 12 to 25 years old. Seventeen patients sustained injuries to the spinal cord in sports and recreation related activities. Twenty-three patients had lesions of the spinal cord above the sympathetic outflow. Twenty patients developed gastroduodenal perforation or bleeding within 4 weeks following the injury. Ten patients developed perforation of gastric or duodenal ulcer and “shoulder tip” pain was a symptom of perforation in six patients. Six patients of seven who had gastroscopy and upper GI series were found at laparotomy to have ulcers. Gastric (nine) and duodenal (seven) ulcers were evenly distributed. There were no deaths due to gastroduodenal hemorrhage in the present series. A single cause for the pathogenesis of gastroduodenal ulceration and hemorrhage cannot be pinpointed. However, ischemia of gastric mucosa produced in various ways and altered equilibrium between the parasympathetic and sympathetic neural pathways following trauma to the spinal cord seem to be important in initiating the process.