Knowledge of the cleanliness of reproductive organs during menstruation is very important knowledge because good knowledge can impose on the health of a person. Behavior is an individual response to a stimulus or action that can be observed and has a specific frequency, duration, and purpose, whether consciously or unconsciously. The research method used is a descriptive research design. The sampling technique used a total sampling of 84 respondents. The results of this study indicate the knowledge of female students in maintaining the cleanliness of their reproductive organs during menstruation. Research conducted by researchers at STIKes Santa Elisabeth Medan, obtained from 84 respondents, that 83 respondents (98.8%) had good knowledge and results behavior in maintaining the cleanliness of their reproductive organs during menstruation were obtained that 65 respondents (77.4%) behavior good. The conclusion is that the knowledge and behavior of female students in maintaining the cleanliness of the reproductive organs during menstruation is glare It is hoped that students at STIKes Santa Elisabeth Medan, can maintain a clean and healthy life.