Paragangliomas (glomus tumors) are slowly growing, mostly benign tumors of the parasympathetic ganglia which most frequently occur in the head and neck region. Between 10% and 50% of cases are familial and follow an autosomal dominant mode of inheritance. The trait is maternally imprinted and exclusively transmitted through the paternal line. To date, two loci have been implicated in this disorder: one at 11q23 (PGL1), the other one at 11q13 (PGL2). We have analyzed a large German family with hereditary paraganglioma, but no evidence of maternal imprinting. By linkage analysis with markers flanking both PGL1 and PGL2, we demonstrate that the trait does not segregate with either of the loci at 11q. Our findings show that a third locus, PGL3, can be involved in hereditary paraganglioma.