A rodent model of hereditary cancer in which a single gene mutation predisposes rats to bilateral multicentric renal cell carcinoma (RCC) is described. This rat hereditary cancer syndrome shares certain similarities with von Hippel-Lindau disease (VHLD). In addition to the early development of renal epithelial tumors with morphologic similarity to human RCC, rats which bear the RCC gene are predisposed to the development of secondary primary cancers later in life. Splenic vascular proliferative lesions, including hemangiosarcoma, were seen in 23% of 14-month-old rats of both sexes that had renal tumors. At fourteen months of age, 62% of female rats with renal cell tumors had sarcomas of the lower reproductive tract of probable smooth muscle origin. Non-carrier siblings of affected animals did not have renal, reproductive, or splenic neoplasia. The finding of a specific constellation of familial neoplasms, including multicentric bilateral renal cell carcinoma, in this autosomal dominant disorder of rats suggests that this syndrome is analogous to human VHLD. In addition to its usefulness for studies of the biochemical and molecular mechanisms of renal carcinogenesis, this animal model will provide a unique tool to investigate how cancer susceptibility genes interact with environmental risk factors such as chemical carcinogens.