Although the arthritis of sickle cell anemia has generally been considered noninflammatory, published studies suggest the existence of an inflammatory variety. The common association of bone abnormalities with inflammatory arthritis precipitated a radiographic evaluation of 100 patients, chosen at random from those followed at the University of Tennessee Sickle Cell Center. Erosive disease was identified in 14 percent. This was correlated with clinical manifestations in a longitudinal manner. Loss of definition of the cortical margin in the superior aspect of the calcaneus appears to be erosive in nature. It has not been observed previously and may be pathognomonic for sickle cell anemia. Arthrographic and gross pathologic material is presented in support of this hypothesis.