Tibiotalar slant is a particular angled deformity of the ankle mortise described in juvenile rheumatoid arthritis, hemophilia, multiple epiphyseal dysplasia, and more recently in sickle cell anemia. True tibiotalar slant is probably due to premature closure of the lateral portion of the distal tibial epiphysis initiated by ischemia. The original observation of this finding in sickle cell anemia indicated an incidence of 14 out of 36 patients (39%). Our prospective study which eliminated the positioning artifact of pseudotibiotalar slant revealed a slanted ankle mortise in only one of 28 (3.6%) homozygous sickle cell anemia patients. Further, the finding failed to correlate directly with hematologic variables or clinical severity of the disease. We conclude that the observation of tibiotalar slant in sickle cell anemia patients is presently of limited diagnostic or clinical research value. Its observation in sickle cell anemia leads to speculation that the etiology of the deformity in other clinical conditions is also related to ischemia of a portion of the growth plate.