Skeletal involvement of non-Hodgkin's lymphoma is found in 11-16%, in Hodgkin's disease in 7.6-34%. Primary lymphoma of bone has an incidence of 1-50% among all non-Hodgkin's lymphoma. The occurrence of skeletal lesions is higher in infants and children than in adults. Skeletal lesions caused by Hodgkin's and non-Hodgkin's lymphoma are mostly seen in the axial skeleton including the skull, whereas the primary lymphoma of bone seems to prefer a more peripheral site. The aggressiveness of the tumor growth can be measured by the method of Lodwick, by judging the edge characteristic, the penetration of the cortex, the periostal and sclerotic reaction. 3 examples illustrate this method. Conventional radiographs need only be performed when there is reason to believe a lesion is located in an area of structural importance, such as the neck of the femur, and in cases of skeletal pain of unknown origin.