Sickle-cell anemia is a hereditary and familial chronic hemolytic anemia resulting from abnormalities of the hemoglobin molecule and is distinguished by peculiar sickle-shaped red blood cells. It is clinically characterized by anemia, abdominal crises, joint pains, leg ulcers, and other manifestations depending on the organs involved. These manifestations stem from the basic pathologic processes of excessive blood destruction, abnormal erythropoiesis, thrombosis, and infarction. It is to be differentiated from the sickle-cell trait in which there is neither anemia nor reputedly clinical manifestations, but in which the erythrocytes may be made to sickle under proper conditions. It should be noted, however, that Bauer (1) has described cases in which bone and joint pain and acute abdominal pain were attributed to the sickle-cell trait in the absence of anemia. Wintrobe (2) and others feel that the trait is harmless except that it can be transmitted, and that the evidence offered so far is not adequate to prove the existence of clinical manifestations in the absence of anemia. While sickle-cell disease has been described in other races including whites (3–7) it is essentially peculiar to the Negro. The sickling trait has been estimated to occur in approximately 7 per cent of the North American Negro population. It is generally believed that 1–2 per cent of those with sickle-cell trait develop the hemolytic anemia (8). The skeletal changes which may occur in sickle-cell disease have been reported by numerous authors (9–15). These osseous abnormalities include widening of the medullary cavities with thinning of the cortices and coarsening of the trabeculae, osteoporosis, osteosclerosis, narrowing of the medullary cavity with thickening of the inner aspect of the cortices in long bones, cupping of demineralized vertebrae, and aseptic necrosis. Such bone derangements presumably reflect the marrow hyperplasia, thromboses, and infarctions characteristic of sickle-cell anemia. It is the object of this article to present 5 cases of sickle-cell disease, all of which showed roentgenographic evidence of an aseptic necrosis of bone but with a variation of clinical complaints, ages, associated osseous abnormalities, and hematologic findings. Case I: C. R., a 38-year-old colored male baker, was first admitted to the hospital Oct. 24, 1950, complaining of pain in both hips and the left shoulder of four years duration. Physical examination revealed marked limitation of passive abduction and rotation of the left shoulder and pain with marked limitation of motion in all planes in both hips. There were, in addition, numerous abnormal neurological findings. The blood count showed hemoglobin 14 gm., 4,650,000 red blood cells, 5,900 white blood cells, with 57 per cent neutrophils, 40 per cent lymphocytes, 3 per cent monocytes. Alkaline phosphatase was 3.8 Bodansky units; phosphorus 2.9 mg. per cent; calcium 10.9 mg. per cent. Kline and Mazzini tests were negative.