The purpose was: 1) to determine annual incidence rates of adult coeliac disease, 2) to calculate the risk of having developed coeliac disease in adult life, and 3) to calculate the life time prevalence by five-year birth cohorts. All patients fulfilling defined criteria for adult coeliac disease living in the county of Copenhagen and diagnosed during the years 1976-1991 were included. The reference population consisted of 503,283 subjects. The overall incidence had been stable during the period, and was 1.27/10(5). The figures for females and males were 1.55/10(5) and 0.96/10(5), respectively (p = 0.04). The median (range) age at the time of diagnosis was 40.1 (16-81). Age specific incidence rates varied considerably, with the peak rate located in the middle-aged population. The incidence rates were influenced by age at diagnosis (p = 0.01) and sex (p = 0.04), but not by the year when diagnosed. For a subject aged 89 years, the risk was 0.88/1000. The overall prevalence was 45.9/10(5). In conclusion, this incidence/prevalence is one of the lowest reported, and is definitely lower than prevalences reported from our neighbouring Scandinavian countries. Nothing points to higher incidence rates being present in Danish adults to compensate for the previously demonstrated very low rates in Danish children.