Idiopathic myelofibrosis is a chronic myeloproliferative disease characterized by skeletal lesions (30 to 70% of cases). We considered 49 patients with idiopathic myelofibrosis treated between 1972 and 1986 at the Institutes of Hematology and Radiotherapy, University of Bologna. Only 19 of these patients underwent roentgenographic skeletal surveys, associated with whole body bone scintigraphy in 4 cases, and with CT in 1 case. The most common bone change, as seen in 12 patients, was osteosclerosis, following two distinct patterns: pure, and mixed. Other types of bone involvement (osteoporosis and pure osteolysis) were seen in 2 cases only; in 5 patients radiological skeletal examinations did not show meaningful lesions. Conventional radiology is hardly ever conclusive in the diagnosis of idiopathic myelofibrosis. This is due partly to the often moderate degree of bone involvement, partly to the scanty specificity of the findings. However, a careful examination of the plain roentgenographs, completed when possible by other more recent imaging techniques, may be very important towards a more precise definition of the disease and, in some cases, for a correct diagnosis.