Hypertension is a multifactorial and heterogeneous disease caused by the addition of environmental and genetic factors. Heritability of systolic and diastolic blood pressure has been well established. Among 6,594 hypertensive patients studied in our clinic, 42% had a history of hypertension in one of their parents and in this group, 13% also had a hypertensive sibling. Anamnestic but not clinical features of patients with familial hypertension slightly differ from patients without familial hypertension. A general strategy is proposed to test the hypothesis that genes known to regulate blood pressure are also responsible for liability to hypertension. In a preliminary report, a study of the TaqI polymorphism of the human renin gene did not reveal a significant difference between hypertensive patients with a family history of hypertension and normotensive controls. A linkage study with DNA markers in informative families is also proposed as an alternative.