Admissions to hospital in the Republic of Ireland, in Scotland, and in England and Wales for coeliac disease and cystic fibrosis are compared. Admissions to hospital in 1972 for coeliac disease in the Republic of Ireland—which does not yet have full returns of hospital admissions—was approximately three times greater than the number expected based upon the rates in England and Wales in 1969–71. In Scotland the admission rates for coeliac disease were about twice the expected number based upon the English rates. This contrasted with admissions for cystic fibrosis which were only slightly higher in Ireland and in Scotland than in England and Wales—evidence that the high admission rates for coeliac disease represent a genuinely high rate in the community. Admission rates for coeliac disease were as high in the East and South of Ireland as in the West. In Ireland the potato, and not wheaten bread, was the staple diet before the great famine of the 1840s. In nineteenth-century Scotland, too, less wheaten bread was eaten than in England and Wales. In the past, therefore, coeliac disease would not be as disadvantageous in Ireland, and to a less extent in Scotland, as in England and Wales.