The clinical manifestations of sickle-cell anemia have been known for many years. It was first suggested by Bauer and Fisher,1 in 1943, when they described manifestations noted in the "nonanemic variety of sickle-cell disease," that sickle-cell trait, the heterozygous state of the sickle-cell gene, can cause symptoms. Since that time an increasing number of reports have stressed the point that vascular occlusions leading to clinical symptoms may occur in persons harboring sickle-cell trait or in others demonstrating newly discovered abnormal hemoglobin variants. Only recently have sickle-cell disease and its genetic variants been demonstrated as a cause of gross hematuria. Only too often hematuria without readily demonstrable cause is a major concern to the urologist. Frequently these cases are first seen by the internist or general practitioner, who refers them for urologic investigation only to have complete genitourinary clearance given. Whenever so-called essential, or idiopathic, hematuria is diagnosed in a