Dietary n-3 polyunsaturated fatty acids (PUFAs) intake is known for its beneficial effects on cardiovascular disease and could be considered as a possible prevention in the developpment of hypertension. The goal of the present study was to evaluate the influence of n-3 PUFAs on cardiac membrane fatty acid profile after a 8-week period of nutritional experiment in several etiologies of hypertension. i) Essential hypertension with cardiac hypertrophy (CH) was investigated through the use of SHR (Spontaneous Hypertensive Rat). ii) Central hypertension was represented by the "fructose-fed rat" that exhibits insulin resistance parallel to mild hypertension (without CH). iii) A severe peripheral hypertension (with CH) was induced by a stenosis of the left renal artery, a surgery described as mode! of Goldblatt 2K l C rat (2-lddney, !-clip). Severa! experiments were carried out, investigating each of the described etiologies with regard to their corresponding normotensive controls. Hypertensive and normotensive rats were fed a diet containing (or not for NFD, Normal Fat Diet) either EPA (20:5 n-3, eicosapentaenoic acid) or DHA (22:6 n-3, docosahexaenoic acid). The rise in BP, heart rate were monitored using either indirect tail-cuff measurements or an intra­ abdominal telemetry system.The data indicated a reduced rise in BP in both DHA and EPA groups, in hyperinsulinemic and Goldblatt 2K, 1C rats as compared to control. A similar result was obtained in SHR receiving DHA, but not EPA. The myocardial phospholipid fatty acid profile was significantly affected by dietary DHA intake, Jess by EPA intake. Inparallel in hypertensive NFD rats hypertension induced specific impairments of these membrane compositions (enhanced total n-6 PUFAs, deficiency in n-3 PUFAs, decreased n-6/n-3 ratio, ...), more pronotmced in case of CH. These tendancies disappeared with dietary n-3 PUFAs intake, especially DHA. Membrane impairments and physiological events translating hypertension were more pronounced when the diet was n-3 PUFA-free. Dietary n-3 PUFAs, especially DHA, exhibit beneficial preventive effects on hypertension whatever its etiology.