Although the term polycystic diseases is usually associated with the kidneys, invovlement of other organs such as the liver, pancreas, spleen and lung is not uncommon. However, in many such cases the polycystic disease is found only at autopsy or is an incidental finding during laparotomy. Eight patients with polycystic liver and kidney disease were examined with gray-scale ultlrasonograhy. The value of gray-scale ultrasound as a noninvasive means of differing cystic disease from suspected neoplastic disease is emphasized.