['To assess intraindividual variation of follicle stimulating hormone, luteinising hormone, estradiol, progesterone, inhibin A, and inhibin B in three successive ovulatory cycles correlated with transvaginal ultrasound monitored morphological changes in the ovary.', 'Serial transvaginal color and pulsed Doppler ultrasound and serum hormone analysis were performed during midfollicular, periovulatory, and midluteal phase for three consecutive cycles in 19 patients with normal menstrual cycles.', 'Luteinising hormone and progesterone showed significant differences in the midluteal phase between the 1st and 2nd cycle (luteinising hormone p = 0.007 and progesterone p = 0.02). Progesterone showed a similar significant change (p = 0.013) between the 2nd and 3rd cycle. No significant differences were seen in the midfollicular or periovulatory phases or between the 1st and 3rd cycle.'] Is intraindividual hormonal variability in ultrasonographically timed successive ovulatory menstrual cycles detected only in the luteal phase in infertility patients?