Peptic ulcer disease usually has periodic exacerbations and remissions. Pain can disappear without total healing of the ulcer crater and can be absent when an ulcer is present. Changes in the incidence of ulcer disease have been noted in recent years. Genetic predisposition, infection with H. pylori, and the use of anti-inflammatory drugs are involved in causation. Stress; the use of alcohol, tobacco and caffeine; and other diseases have been implicated as etiologic factors. Ulcer pain has a recognizable pattern, but the symptoms can be variable, particularly in older people and in patients taking ulcerogenic medications. The familiar complications of hemorrhage, perforation, and obstruction still occur, and nonulcer dyspepsia has not been fully explained. Duodenal ulcers have a disturbing tendency to return; new therapeutic approaches offer hope.