peer reviewed ; An estimation of the incidence and demographic picture of the major haemoglobinopathies in Belgium has been approached through a confidential inquiry sent to 228 haematological departments. Forty two percent of responses have shown that 417 patients are known in Belgium: 83% with sickle cell disease, 13% with -thalassaemia major, 2% with -thalassaemia intermedia, and 1% with haemoglobin H disease. Twenty five percent of the sickle cell disease patients and 54% of those suffering from a -thalassaemia major were older than 20 years. Three hospitals insure the follow-up of 70% of the patients and are situated in Brussels; in 21 centres a follow-up of less than 20 patients was reported. Those results confirm that sickle cell disease is the first major haemoglobinopathy in Belgium; it concerns mostly paediatricians but adult haematologists are also confronted with those pathologies. Therefore, it is necessary to implement integrated programs of prevention and treatment.