The number of elective operations for chronic peptic ulceration has decreased substantially with the widespread use of H2-receptor antagonists. We have reviewed all cases of perforated peptic ulcer in Oxford over the last 18 years (1965-82) to see if a similar change in the incidence of this major complication of peptic ulceration has occurred. Since 1976 there has been a fall in the incidence of perforated peptic ulcer from 8.7 to 6.9 cases per 100 000 population per year. The male to female ratio decreased over the review period from 4.9:1 to 1.9:1 owing to a reduced incidence of perforation in men and an increased incidence in women. The mean age of men with perforated duodenal ulcer increased from 52.3 years in 1965-70 to 59.0 years in 1977-82. One hundred and sixty-six patients treated between 1977 and 1982 have been reviewed in detail. The overall mortality in this 6 year period was 12.7 per cent with an operative mortality rate of 8.9 per cent. The majority of perforations (65 per cent) are now of acute ulcers and therefore are unlikely to be prevented by improved therapy for chronic peptic ulceration.