OBJECTIVE: To evaluate the demographics and incidence of Barrett’s oesophagus diagnosis using community-based data. DESIGN: Observational study. SETTING: Kaiser Permanente, Northern California healthcare membership, 1994-2006. PATIENTS: Members with an electronic diagnosis of Barrett’s oesophagus. MAIN OUTCOME MEASURES: Incidence and prevalence of a new Barrett’s oesophagus diagnosis by race, sex, age and calendar year. RESULTS: 4205 persons met the study definition for a diagnosis of Barrett’s oesophagus. The annual incidence in 2006 was highest among non-Hispanic whites (39/100,000 race-specific member-years, 95% confidence interval (95% CI) 35 to 43), with lower rates among Hispanics (22/100,000, 95% CI 16 to 29), Asians (16/100,000, 95% CI 11 to 22), and blacks (6/100,000, 95% CI 2 to 12). The annual incidence was higher among men than women (31 vs 17/100,000, respectively, year 2006; p<0.01). The incidence increased with age from 2 per 100,000 for persons aged 21-30 years, to a peak of 31 per 100,000 member-years for persons aged 61-70 years (year 2006). There was no increase in the incidence of new diagnoses until the last two observation years, which coincided with changes in data collection methods and may be due to bias. The overall prevalence among active members increased almost linearly to 131/100,000 member-years by 2006. CONCLUSIONS: The demographic distributions of Barrett's oesophagus differ markedly by race, age and sex and were comparable to those for oesophageal adenocarcinoma. Thus, demographic disparities in oesophageal adenocarcinoma risk may arise partly from the risk of having Barrett's oesophagus, rather than from differing risks of progression from Barrett's oesophagus to cancer. There has been an almost linear increase in the prevalence of diagnosed disease.