A highly metastatic LCI-D20 model of human hepatocellular carcinoma (HCC) was obtained via orthotopic implantation of a histologically preserved metastatic tumour selected from 1 of 30 surgical specimens, and had been maintained for 18 passages in nude mice. All mice with transplanted tumours exhibited 100% transplantability and metastatic ability, as well as various manifestations reminiscent of tumour behaviour in HCC patients. These included: local growth, regional invasion, spontaneous metastasis to liver, lymph nodes and lungs, and peritoneal seeding. Histological characteristics of the LCI-D20 tumour were similar to those of the original tumour. Karyotypic analysis revealed heteroploid cells. Immunohistochemically, expression of AFP and HBxAG was shown. Our nude mouse model with its high metastatic rate and short latency period could be an interesting tool for the study of human HCC.