Acquired renal cystic disease is common in patients receiving dialysis. Characteristically, the kidneys are small or, less often, normal in size, and the cysts are usually less than 0.6 cm in diameter. We present here 2 patients who, after 5 and 7 years on hemodialysis, developed marked renal enlargement, with large cysts in the kidneys and, in 1 patient, in the liver as well; the appearance on ultrasonography and computed tomography was indistinguishable from autosomal dominant polycystic kidney disease. Before starting dialysis the first patient was a 19-year-old man who developed renal shutdown from crescentic glomerulonephritis, and the second patient was a 33-year-old man who developed end-stage renal failure from malignant hypertension. Neither patient had renal cysts at the onset of end-stage renal failure.