von Hippel-Lindau disease (VHL) is a rare autosomal-dominant disorder in which affected individuals develop tumors in a number of locations. It occurs at a frequency of one per 36,000 population. Metastatic renal cell carcinoma (RCC) remains the leading cause of mortality in patients with clear cell RCC arising from mutations in the VHL tumor suppressor. RCC is the presenting feature in only 10% of VHL patients. VHL patients can present with a number of other renal lesions, such as hemangiomas and benign adenomas, in addition to simple cysts and RCC. We have investigated VHL gene mutations in familial RCC. The study cohort consisted of four patients with synchronous VHL and RCC and 31 kindreds. Analysis of the chromosomes was performed by the Moorehead method. Although none of the kindreds investigated had clinical evidence of VHL disease, 22 were found to have a VHL gene mutation consisting of deletions on the short arm of chromosomes 3, 17, and 19. Detailed clinical examination of the 22 kindreds with a VHL mutation revealed cerebellar hemangioblastoma (three kindreds), meningioma (two) and renal cell carcinoma (five). No VHL gene mutation was detected in nine kindreds. The prevalence of VHL gene mutations was 70.9% in the familial RCC kindreds. As a result of this study, the kindreds of patients with synchronous VHL and RCC have undergone molecular genetic testing and should be investigated for associated disorders.