Although the incidence of stomach hemorrhage is declining, stress-related gastric bleeding remains an important source of morbidity and mortality in cancer patients undergoing major surgical procedures to remove tumor. Prevention of stress-related bleeding is desirable; however, the optimal use of drugs to prevent gastric bleeding is unclear. Prophylaxis is recommended for surgical patients who require prolonged mechanical ventilation or have a coaguloathy. Histamine-2 receptor antagonists and sucralfate will reduce the likelihood of clinically important gastric-bleeding. Sucralfate appears to be less effective than H-2 blockers, but it is associated with fewer side effects such as nosocomial pneumonia. Preliminary studies show that proton pump inhibitors are most effective, have few side effects, but are most expensive. Intravenous proton pump inhibitors may be the drugs of choice for stress ulcer prophylaxis (SUP) in high-risk patients.