Stress gastric erosions are in fact the gastroduodenal expression of a most disseminated injury involving whole organism. Ischemia represents the main factor leading to the decrease of gastric mucosa protective mechanisms. The most important complication of stress ulceration is acute bleeding. Gastrointestinal hemorrhages of clinical relevance are now so scarce that widespread systematic prophylaxis against stress ulcers can be safely withheld. Supportive therapy of associated acute organ failure remains the most accurate prophylaxis. Patients who are the most likely to benefit from specific prophylaxis are still unknown.