The purposes of this study were to measure menstrual knowledge, assess menstrual health care behavior and investigate the factors associated with menstrual health care behavior among fifth and sixth grade female students. The subjects were 417 female students from 12 elementary schools in the Hualien region of Taiwan. The stratified cluster random sampling method was adopted. The questionnaire used in the study consisted of three sections: personal information, a menstrual knowledge questionnaire, and a menstrual health care behavior questionnaire. The results of this study show that the majority of the respondents felt that menstruation had an influence on their emotions (74.8%), daily life (73.1%), schoolwork (61.6%), and social interaction (50.1%). The total correct response rate for the menstrual knowledge questionnaire was 45.1%. There was a significant difference between aboriginal and non-aboriginal female students in terms of the correct answer rate for the menstrual knowledge questionnaire. The mean score for menstrual health care behavior was 2.66 (SD = 0.82). Elementary level female students who had better menarche preparation scored higher on the menstrual knowledge questionnaire, and those whose first period had already occurred felt more confident in their ability to execute proper menstrual health care behavior. The results prompted the recommendation to families and elementary schools to encourage students to improve their menstrual health care behavior during menses.