Eighty college women were queried about their knowledge of three aspects of the menstrual cycle (menstruation, ovulation, and menopause). Questions concerned the biology of each event and the physical, emotional, and cognitive changes believed to be associated with them. Reasoning from the biases and limitations in the scientific and popular literature, it was predicted that: (1) women would be relatively uninformed about the menstrual cycle, but more informed about menstruation than about ovulation or menopause, and (2) negatively valued changes would be described more frequently than positively valued ones. Results indicated that basic knowledge of the menstrual cycle, even among well educated women, is at times incorrect, generally incomplete, and negatively biased. These findings confirm the need for a more comprehensive approach to menstrual education that speaks both to the biology of the menstrual cycle and to norms and variability of associated physical and behavioral changes.