The authors collected observations concerning 11 newly histologically proved cases of a combination of Paget's disease and carcinoma metastatic to bone on the same bone from members of the French Rheumatology Society. The most frequent locations can be specified from their analysis and an analysis of 26 detailed cases from the literature, i.e. pelvis, femur, rachis, tibia, humerus, and the cancers most frequently involved--prostate, bronchi, kidney, breast and intestine. The most usual histological appearance is osteolytic, except in the case of prostatic carcinoma. The metastasis reveals the presence of cancer in 2 cases out of 3, whereas Paget's disease is most often already diagnosed. A histological examination is necessary because of the risk of non recognition of such metastases or of confusion with sarcomatous degeneration. It does not appear to be exceptional to find Paget's disease in combination with a metastasis on the same bone. Although six of the cases concern metastases only located at sites of Paget's disease, an analysis of all the cases does not seem to indicate that Paget bone is more exposed to metastases than normal bone, since both diseases in fact locate preferentially at the same sites on the skeleton.