PROGRESSIVE renal failure, when present in such varying diseases as chronic glomerulonephritis, chronic pyelonephritis, hydronephrosis, arteriolonephrosclerosis, and polycystic kidneys, is usually characterized by common clinical manifestations. Hypertension, retinopathy, edema, anemia, nitrogen retention, albuminuria, and cylindruria are usually present at some time during the course of the disease. Exceptions occur, of course, but in general the late manifestations are quite constant, regardless of the underlying renal process. This paper deals with four cases which deviated consistently from this typical clinical pattern. In all these cases the kidneys were found to be small and contracted and to contain numerous medullary cysts. The clinical picture was characterized by insidious uremia and anemia alone, unaccompanied by the other stigmata of progressive renal failure. Three of these were taken from the files of the Presbyterian Hospital and one from the files of Dr. Warfield T. Longcope. In addition, reference is made to two cases from