An autosomal dominant pattern of transmission has been established for polycystic kidney disease. The degree of cystic involvement of other organs has been variable. The genetic pattern of transmission of polycystic liver disease independent of cystic kidney disease has never been established. We present a second family with polycystic liver disease without kidney disease. The lack of renal cysts is unlikely to be due to variable expressivity and penetrance of the gene for polycystic kidney disease. The liver cysts may be of late onset since none of the proband's four children demonstrate cysts. Alternatively, none of these four individuals may have received the gene for polycystic liver disease from their affected mother. The family described supports an autosomal dominant pattern of inheritance for polycystic liver disease.