Background: The necessity to educate schoolgirls regarding menstruation and appropriate menstrual hygienic practices by using a suitable program especially in schools. This study aimed to evaluate the effect of an education program on secondary school girls' menstrual health in Khartoum, Sudan. Methods: This study was quasi-experimental (one group pre/posttest). The study was conducted on secondary-school girls, Khartoum, Sudan, from July to August 2018. The school consists of 11 classes for the three levels, the first level 4 classes, second-year 3 classes, and third year 4 classes and the total number is 400 students. One class was chosen randomly from each level (three classes involved). Non- probability sampling technique, a convenient sample of 60 secondary school students was included in the study (20 from each class) 50 students completed the study, and 10 students withdrew. The data were collected by using a validated questionnaire, which consists of three parts, part one is socio-demographic data of the students, part two is student's knowledge about menstruation, and part three student's hygienic practices during menstruation. The data were analyzed by SPSS version 20, and appropriate tests were applied. Results: The overall schoolgirls' knowledge was significantly improved from 25% to 76.14% after the intervention and the key source of information was their mothers followed by teachers. The hygienic practice was insignificantly improved from 27% to 39.4% after the intervention. Conclusion: This study concludes that menstrual health education for schoolgirls has significantly improved the knowledge and hygienic practice on menstrual health. Recommendation: It is recommended to conduct further research with a more representative sample that could show the appropriate effect. Consequently, the outcome of this study is a part of the school health program and a base for further interventions at this age group.