 Although stress ulcer is a complication that can cause mortality and morbidity in critical patients, there is still lack of consensus about its prophylaxis. There is also few data available from Taiwan. H2 blockers are commonly used due to convenience. Some prefer sucralfate a mucosal protective agent for the sake of less associated nosocomial pneumonia. Recently, proton pump inhibitors were shown to have good prophylactic effects for stress ulcer. Esomeprazole, an isoform of omeprazole, has good acid suppression effect and the tablets are soluble for the use of tube feeding. Our previous study showed that there was no difference for the efficacy of stress ulcer prophylaxis between esomeprazole and sucralfate in patients admitted to medical ICU with at least one risk factor. The prevalence of nosocomial pneumonia was also similar. 