A variety of organic etiologies are associated with peptic ulcer disease, and the most relevant of these are infection with Helicobacter pylori and use of nonsteroidal anti-inflammatory drugs. Between 5% and 20% of patients with gastric or duodenal ulcer, however, lack an identifiable organic etiology. In these patients particularly and in all ulcer patients in general, psychosocial factors may play a significant role. At present, there is no definitive study proving a causal relationship between psychological stress and the development of ulcer disease. Studies to date suffer from significant methodological limitations and have not effectively addressed the poor correlation between ulcer craters and ulcer symptoms. A conservative application of available data would suggest that psychosocial factors play a significant role in symptom perception and reporting in patients with dyspeptic symptoms and may play a role in ulcer formation.