This study examined the effects of high dietary lard on the cardiovascular system responsible for regulating blood pressure in the spontaneously hypertensive rat (SHR), a model of essential human hypertension. The fat contents were 4.5% of diet weight for control diet and 20% for high-lard diet, respectively. Four-week-old male SHR animals were fed the diets for 9 weeks. After 9 weeks of feeding, the cardiovascular responses to the intravenous administration of vasoactive drugs were determined in conscious SHR animals. The pressor responses elicited by the α₁-adrenoceptor agonist phenylephrine were diminished in high-lard-fed SHR animals. The depressor responses elicited by the ß-adrenoceptor agonist isoproterenol were equivalent in the high-lard-fed SHR and control SHR groups. The depressor responses elicited by the nitric oxide donor sodium nitroprusside were equivalent in both dietary groups. The depressor responses elicited by the endothelium-dependent agonist acetylcholine were diminished in high-lard-fed SHR animals. Baroreceptor reflex-mediated changes in heart rates in response to changes in mean arterial blood pressure (MAP) elicited by phenylephrine and sodium nitroprusside were diminished in the high-lard-fed SHR group. Despite the diminished endothelium-dependent vasodilation and impaired baroreflex function, resting MAP values were similar in both dietary groups. These findings suggest that high dietary lard does not exacerbate hypertension in the SHR model.