The Authors describe the laparoscopic aspects of spontaneous human ovulation and correlate it with the evaluation of basal body temperature, the total urinary oestrogens, pregnanediol and urinary LH and some hematic values of 17-beta-estradiol, 17-alpha-Hydroxyprogesterone and rogesterone. They find that the rise in temperature and the oestrogenuria peak precede ovulation by some hours in the great ovulation by sompe hours in the great majority of cases. They analyze the validity of the other parameters studied, and show a relatively constant behavior, with regard to ovulation, in the mean evaluation of several cases. In the individual analysis, on the contrary, this relation is difficult to find and less significant. The Authors stress the importance of comparing the physico-chemical evaluations with the biological phenomenon of ovulation directly ascertained by means of laparoscopy.