Objective To investigate the application effect of case-based teaching versus traditional teaching in the optional course of maternal and child nutrition for medical undergraduates.Methods The students who completed the course through the traditional teaching method in 2016 were enrolled as control group,and those who completed the course through the case-based teaching method in 2017 were enrolled as experimental group.In the process of teaching,the teachers in the experimental group needed to write cases,prepare lessons collectively,give guidance and inspiration,and summarize after class.During the learning process,the students in the experimental group needed to collect information before class and perform role play,group discussion,and intergroup communication about the case during class.After the course ended,a questionnaire for nutrition during pregnancy preparation,pregnancy,and lactation,breastfeeding,and complementary feeding was developed for assessment.With sex and grade as related factors,SPSS 18.0 was used for the chi-square test of two sample rates according to knowledge points,and the correct rate of each item was analyzed.Results A total of 107 valid questionnaires were collected from the control group,and 109 valid questionnaires were collected from the experimental group.For the questions on the knowledge of maternal and child nutrition,the experimental group had slightly higher correct rates than the control group (all P＞0.05).For the questions on the comprehension and practical application of the knowledge of maternal and child nutrition,the experimental group had significantly higher correct rates than the control group (all P＜0.05).Further stratified analysis based on sex and grade showed that the experimental group had higher correct rates than the control group.Conclusion Compared with traditional teaching,case-based teaching may not have advantages in enhancing students' memorizing ability,but it can make it easier for students to understand the theoretical knowledge of matemal and child nutrition and master the practical application of such knowledge.