We previously demonstrated involvement of the medial amygdaloid nucleus in restraint stress-induced pressor responses in rats. In this study, neuronal perikarya in the medial amygdaloid nucleus of 4-week-old spontaneously hypertensive rats (SHR) were selectively destroyed with ibotenic acid. Bilateral lesions of the medial amygdaloid nucleus attenuated the development of hypertension in SHR. Body weight gain was not different between lesioned and sham-lesioned SHR throughout the experimental periods. These data suggest that neurons in the medial amygdaloid nucleus may be involved in the development of hypertension in SHR.