Twenty-five children and adults with concomitant coeliac disease and selective IgA deficiency are described. IgG-class reticulin antibodies were positive in 94%. The clinical course of coeliac disease did not differ from that of patients with normal serum IgA level. Patients with IgA deficiency also had other concomitant diseases, especially autoimmune diseases. Patients with selective IgA deficiency have at least a tenfold risk of coeliac disease compared with the population in general.