Polycystic liver disease (PCLD) without polycystic kidney is infrequent in clinical setting. Family clustering is found in patients with PCLD, and it is inherited in an autosomal dominant fashion. Through positional cloning in North America and Europe (mostly in Dutch and Finnish descents), mutations in PRKCSH gene on chromosome 19 were found to be responsible for the disease. We investigated the prevalence of liver cysts and PCLD in Taiwan and investigated whether the PRKCSH mutations exist in Taiwanese. The prevalence of liver cysts is only 0.17% in people under 30 years old and increased gradually to 14.29% in people between 55 and 60 years old and 14.19% in people over 65 years old. PCLD was not found in people under 40 years old. The prevalence is 0.15% between 40 and 45 years old, and increased to 1.37% between 55 and 60 years old, 1.21% between 60 and 65 years old, and 0.99% over 65 years old. There is only one polymorphism (deletion of one GAG repeat in exon 11) found, and the genotype and allele frequency were the same in Taiwanese patients and controls. No mutation, even polymorphism reported in the literature, was found in the 20 cases of PCLD. Our results suggest that PRKCSH gene is not a major genetic cause of PCLD and there may be at least another locus responsible for the disease in Taiwan.