Although the incidence is decreasing, stress-related erosive syndrome causes overt bleeding in 0.6-6% of critically ill patients. The use of prophylactic medicine and advances in the care and endoscopic treatment of the patients is responsible for this decrease. The two main factors in the development of the stress-related erosive syndrome are ventilation lasting more than 48 hours and coagulopathy. General preventive measures such as fluid resuscitation, control of sepsis and adequate tissue oxygenation is essential to prevent stress-related erosive syndrome. Prophylaxis may be divided in tree groups: neutralization of the gastric acid (antacids), inhibition of the gastric acid secretion (H-2 blockers, proton pump inhibitors) and reinforcement of the gastric mucosa (sucralfate). Although prophylaxis decreases the incidence of bleeding, a decrease in the mortality is not shown.