In South Korea, the International Baccalaureate (IB) Middle Years Programme (MYP) has been implemented in public education for several years. This article explores the IB MYP's characteristics and educational effects by adopting the grounded theory research approach of Corbin and Strauss (1990, 2015). A total of 27 students from three public middle schools offering the IB MYP in one Korean city participated in interviews. Through the interviews, 151 concepts, 41 sub-categories, and 22 categories were identified. Compared to conventional Korean education, the IB MYP's noticeable traits include student-centered classes, inquiry-based learning, interdisciplinary subjects, writing-centered tests, and an emphasis on the IB learner profile. While these differences may initially pose difficulties for Korean students, they can lead to positive outcomes in the cognitive and affective domains, as well as in interpersonal relationships. Based on the findings, it is recommended that the Korean provincial government should develop a long-term vision both nationally and internationally.