The study was designed to present the incidence of all the haematological malignancies in Basse-Normandie over the period 1997-2004. We extracted the data from the "Registre régional des hémopathies malignes de Basse-Normandie (RRHMBN)", a French registry which belongs to the Association of the French Cancer Registries (FRANCIM). All the malignant haematological diseases were coded using the third edition of the International Classification for Oncologic Diseases (ICD-O-3) and the ADICAP classification, a special version adapted in 2001 for haematology. Five thousand five hundred and ten new cases of malignant haematological disorders were registered over the period 1997-2004. Whatever the department constituting the Basse-Normandie (Calvados, Manche and Orne), no significant difference of incidence was detected. In men, the more frequent malignant disorders were non-Hodgkin's malignant lymphomas (NHML) followed by chronic lymphocytic leukemia and other mature neoplasms, myelodysplastic syndromes (MDS), multiple myeloma (MM), myeloproliferative disorders (MPD), acute myeloid leukemias (AML), Hodgkin's lymphomas (HL), Waldenström's macroglobulinemia (WM) and acute lymphoblastic leukemia (ALL). In women, MM is the third more frequent haematological disorders after NHML and lymphocytic leukaemia and other mature neoplasms, MPD, MDS, AML, Hodgkin's lymphomas, WM and ALL. The other haematological disorders are very rare. We provide the incidence for the main haematological disorders and for the first time we also present the incidence of the different subtypes of the Hodgkin's and non-Hodgkin's malignant lymphomas, mature lymphoid neoplasms, MPD and also MDS. These results are useful for the organization and follow-up of medical care. The development of specialized haematology and active protocols can optimize the management of the older patients. A high quality of the collected data remains necessary for a continuous watching and research on patients with malignant haematological diseases.