Fifteen men and 11 normally ovulating women were each tested twice for cardiovascular stress reactivity, cognitive/behavioral performance, and mood during a variety of stressors. Each women was tested during both the follicular and luteal phase of her menstrual cycle, with men matched for number of days between testing. Although the genders did not differ in blood pressure reactivity during either phase of the cycle, during both phases of the menstrual cycle women exhibited greater heart rate reactivity and tended towards greater cardiac index increases, greater pre-ejection period decreases, and lesser vascular tone relative to men. Additionally, the menstrual cycle was observed to influence gender differences in stroke volume index responses. Specifically, stroke volume index responses for women were significantly greater in their luteal versus follicular phase resulting in a marginally significant pattern whereby women's stroke volume index responses were greater than men's luteally but less than men's follicularly. Men and women also differed in cognitive performance and mood assessment during the tasks, but the majority of these differences were unaffected by the menstrual cycle.