In this study we investigated the effect of intravenous infusion of angiotensin II (AII) on plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in fertile healthy women examined both in the middle follicular phase (MFP) and in the middle luteal phase (MLP). As expected, AII induced a significant increase in blood pressure and plasma aldosterone concentration. In MFP, plasma FSH and LH levels did not show any significant change after AII infusion, if compared to both saline and preinfusion basal values. In MLP, AII significantly increased plasma LH (p less than 0.02 vs. baseline values and p less than 0.01 vs. placebo values), but not plasma FSH. The area under the curve during AII infusion resulted significantly higher than during placebo infusion (p less than 0.001). Therefore, these data demonstrate that peripherally injected AII at pressive dose produces an increase in plasma LH levels in normal women on luteal phase when the circulating concentrations of both estradiol and progesterone are high. The study suggests that AII may have a stimulatory role in the regulation of LH secretion, but this role is closely related to the gonadal steroid plasma levels.