Barrett's oesophagus is a risk factor for the development of oesophageal cancer and for this reason annual endoscopic surveillance has been proposed. In this retrospective study of all patients with Barrett's oesophagus diagnosed in a 12 year period carcinoma had developed in only four patients. The incidence of oesophageal cancer in this series was one in 170 patient years, which means a 30-fold increase compared with the general population. The survival of patients with Barrett's oesophagus was not different, however, from an age and sex matched control population. It is concluded that systematic endoscopic surveillance of patients with Barrett's oesophagus is not indicated.