Psychoneuroendocrine stress responses were studied in normally ovulating women in the follicular, ovulatory, and luteal phases of two consecutive menstrual cycles. Psychologic stress was induced by having the subjects perform a battery of cognitive tasks under time pressure. Blood samples were drawn after each session for radioimmunoassay of 17 beta-estradiol, progesterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone, prolactin, cortisol, and androstenedione. Urine samples were obtained for estimation of adrenaline, noradrenaline, and cortisol. The results showed that psychoneuroendocrine stress responses as estimated by urinary excretion of adrenaline and noradrenaline varied significantly across the menstrual cycle, the highest values being obtained in the luteal phase. Self-reported mood and somatic symptoms showed distinct phase-related changes, with more negative mood states predominating in the luteal and menstrual phases and increased positive mood states in the follicular and ovulatory phases.