A primary endodermal sinus tumour of the liver which developed in a 27-year-old woman is reported. The dimensions of the tumour were 11 x 11 x 9.5 cm. Most parts were friable, haemorrhagic, and necrotic. No metastasis was found, but one part of the tumour was invading the diaphragm directly. Histologically, the tumour had mainly a reticular pattern, and partly a solid pattern, and was characterized by the presence of Schiller-Duval bodies and intra- and extracellular hyaline globules. A small part of the tumour showed a polyvesicular vitelline pattern and glandular structures with enteric differentiation. Serum alpha-fetoprotein was very high (28,500 ng/ml), but carcinoembryonic antigen was within the normal range. Immunohistochemically, most of the tumour cells contained alpha-fetoprotein and alpha-1-antitrypsin. Carcinoembryonic antigen and glutathione S-transferase, which was recently proved to be a useful marker for colonic carcinoma, were detected only in the glandular part Four previously reported cases of primary endodermal sinus tumour of the liver are reviewed.