X-ray pictures of the axial and peripheral skeleton are in haematological diseases important in the primary as well as differential diagnosis. Acute lymphoblastic leukaemia (ALL) in children, multiple myeloma and haemophilia are diseases where the changes are significant.Metaphyseal clear spots, diffuse osteoporosis and suddenly developed compressions of the vertebrae may be the first symptoms which draw attention to possible ALL. Multiple myeloma causes typical changes on the skull, spine, ribs and sternum but only in 10% they are found in the first stage of the disease, as changes on magnetic resonance are decisive. Despite all modern therapy in haemophilia severe articular damage develops (haemarthrosis) which calls even in young people for TEP. The authors analyze in the submitted paper their own material of 62 leukaemias in children, 120 patients with multiple myeloma, 160 with haemophilia, 35 with anaemia and others with lymphomas and osteomyelosclerosis. They demonstrate the most interesting case-histories and compare their own experience with data in the literature.

        Key words: haematological diseases - acute leukaemia - multiple myeloma - haemophilia - X-ray pictures