This study aims to understand the educational meaning of practicum experiences in elementary schools with a high concentration of multicultural students. To this end, a qualitative case study was conducted with ten pre-service teachers who participated in a teaching practicum at “A” elementary school, a multicultural-concentrated school in the Chungbuk region. The main findings are as follows. First, the pre-service teachers encountered difficulties in understanding students due to cultural differences, as well as educational challenges stemming from language barriers. Second, despite initial adaptation difficulties, they experienced growth through the educational challenges of the practicum, including a shift in perceptions of multicultural education and an enhanced sense of efficacy. Third, the pre-service teachers faced four dilemmas during the practicum: (1) the dilemma between cultural diversity and civic values, (2) the dilemma between considering immigrant students and the risk of reverse discrimination against native students, (3) the dilemma between role-sharing in bilingual contexts and teachers’ professional expertise, and (4) the dilemma between professional growth and avoidance mechanisms in multicultural concentrated school practicums. Based on these findings, the study identifies the educational meaning of such practicums as a form of “incomplete transformative learning” and suggests implications for improving future practicum programs in multicultural-concentrated schools.