Two patients were studied with multiple, idiopathic bone infarcts secondarily complicated by the development of fibrosarcoma at the site of infarction. Similar association of these lesions has not been reported in the literature. A brief review is presented of the pathophysiology of caisson disease and bone infarcts. An analysis of other known causes of bone infarcts failed to provide an explanation for the multiple bone infarcts present in these two patients, and similarly no direct relation was found in these cases to other benign bone lesions complicated by malignant-tumor formation.