This paper deals with the question of whether measuring hormones is necessary in eumenorrhoeic infertility patients. The answer presented here is yes, but there are some remaining and debatable problems. In our opinion, eumenorrhoea results from regular folliculogenesis, ovulation and luteal function. To be time- and cost-effective, only a limited number of hormones should be measured and assessment of the luteal phase in an eumenorrhoeic patient by measuring oestradiol and progesterone is questionable. The paper discusses the questions on the basis of the currently available literature.