Familial paragangliomas (PGL), or glomus tumors, are slow-growing, highly vascular, generally benign neoplasms usually of the head and neck that arise from neural crest cells. This rare autosomal-dominant disorder is highly penetrant and influenced by genomic imprinting through paternal transmission. Timely detection of these tumors affords the affected individual the opportunity to avoid the potential morbidity associated with surgical removal, and mortality that may accompany local and distant metastases. Linkage to two distinct chromosomal loci, 11q13.1 and 11q22.3-q23, has been reported, suggesting heterogeneity. We evaluated three multigenerational families with hereditary PGL, including 19 affected, and 59 unaffected and potentially at-risk individuals. Numerous microsatellite markers corresponding to each candidate region were tested in all members of the three families. Confirmation of linkage to 11q23 was established in all three families. The inheritance pattern was consistent with genetic imprinting. Using these data, we were able to provide presymptomatic diagnosis with subsequent removal of tumor from one individual, and to start several others on an MRI surveillance protocol.