OBJECTIVE To determine whether anovulation exists in normally menstruating women. METHODS In a database of 550 consecutive couples seeking pregnancy, results of the midluteal serum progesterone level analysis planned for 7 days before the onset of the next menses were examined in women with predictable cycles shorter than 35 days. RESULTS Of the 550 couples seeking pregnancy, 410 of the female partners (74.5%) were eumenorrheic. Fifteen of these women (3.7%) had apparently anovulatory cycles with a progesterone lower than the normal ovulatory value of 15 nmol/L. Further examination showed that four of the 15 women (26.7%) had an isolated prolonged cycle, whereas an additional four (26.7%) failed to have their sample taken at an appropriate time. One (6.7%) had a low progesterone level that was normal in the subsequent cycle. Two patients (13.3%) were older than 40, both having elevated early follicular follicle-stimulating hormone levels. One patient (6.7%) conceived in the following menstrual cycle without further evaluation. The three remaining women (20%) showed consistently apparently anovulatory cycles. However, the levels were exclusively above the follicular range. CONCLUSIONS Our findings cast doubt on the concept of anovulatory cycles in eumenorrheic women and suggest that further examination of the lower level of ovulatory progesterone may indeed be necessary.