The renin-angiotensin system, both in the circulation and in the brain, is known for its role in the regulation of fluid balance and blood pressure. The brain angiotensin II (Ang II) system is also involved in the control of anterior pituitary hormone secretion, through affecting the secretion of releasing and inhibitory factors into the hypophyseal portal vessels. Ang II controls the release of LH and PRL in a manner that is modified by ovarian hormones, observed only under specific conditions, and localized to particular regions of the brain. The identification of Ang II systems in the pituitary gland and ovary, along with data showing effects of ovarian hormones on the activity of the brain Ang II system, suggests a feedback loop whereby the brain, pituitary, and gonads interact to affect reproductive function.