The U.K. Diamond-Blackfan Anaemia (DBA) Registry was established with the aim of providing a representative database for studies on the aetiology, pathophysiology and treatment of DBA. We have analysed retrospective data from 80 cases (33 male, 47 female) born in the U.K. in a 20-year period (1975-94), representing an annual incidence of 5 per million live births. Ten children from seven families had an apparently familial disorder. 13% were anaemic at birth, and 72.5% had presented by the age of 3 months. 67% had macrocytosis at presentation. 72% responded initially to steroids, and at the time of study 61% were transfusion-independent (45% steroid-dependent) and 39% required regular transfusions. Unequivocal physical anomalies, predominantly craniofacial, were present in 37%, and were more likely in boys (52%) than girls (25%). 18% had thumb abnormalities. Height was below the third centile for age in 28%, and 31% had neither short stature nor physical anomalies. Four children without physical abnormalities had normal red cell indices, and achieved steroid-independent remission, suggesting transient erythroblastopenia of childhood rather than DBA. The birth month distribution of children with sporadic DBA and craniofacial dysmorphism showed a possible seasonality, consistent with a viral aetiology.