College women were asked a series of open-ended questions about their conceptions of menstruation prior to menarche as part of a retrospective study. Their responses were rated as indicating correct information, misinformation, or lack of information. A conceptual analysis of these descriptive data reveals some of the emotional and cognitive limitations of pre-adolescence that lead ostensibly well-informed girls to harbor misconceptions about menstruation. Based on this conceptual analysis, a revised approach to menstrual education is suggested.