The present review examines the clinical and experimental data to support the view that homocysteine and oxidative stress, two alternative risk factors of vascular disease, may play a role in the pathogenesis of primary or essential hypertension. Although the precise mechanism of this disease has not been elucidated, it may be related to impairment of vascular endothelial and smooth muscle cell function. Thus, the occurrence of endothelial dysfunction could contribute to alterations of the endothelium-dependent vasomotor regulation. Hyperhomocysteinemia limits the bioavailability of nitric oxide, increases oxidative stress, stimulates the proliferation of vascular smooth muscle cells, and alters the elastic properties of the vascular wall. The link between oxidative stress and hyperhomocysteinemia is also biologically plausible, because homocysteine promotes oxidant injury to the endothelium. Cumulated evidence suggests that the diminution of oxidative stress with antioxidants or the correction of hyperhomocysteinemia with vitamins-B plus folic acid, could be useful as an adjuvant therapy for essential hypertension. Further studies involving long-term trials could help to assess the tolerability and efficacy of the use of these therapeutic agents.