Recent studies have shown that both innate and adaptive immunity contribute to hypertension. Inflammatory cells, including macrophages and T cells accumulate in the vessel wall, particularly in the perivascular fat, and in the kidney of hypertensive animals. Mice lacking lymphocytes are resistant to the development of hypertension, and adoptive transfer of T cells restores hypertensive responses to angiotensin II and DOCA-salt challenge. Immune modulating agents have variable, but often-beneficial effects in ameliorating end-organ damage and blood pressure elevation in experimental hypertension. The mechanisms by which hypertension stimulates an immune response remain unclear, but might involve the formation of neoantigens that activate adaptive immunity. Identification of these neoantigens and understanding how they form might prove useful in the prevention and treatment of this widespread and devastating disease.