International teaching practicum is an important activity in forming pre-service teachers' professional experience. Therefore, this study aims to explore the professional experiences and biggest challenges of pre-service teachers during their international teaching practicum at Sekolah Indonesia Kuala Lumpur, Malaysia. This study involved three participants, using their online interviews and teaching reports as evidence of their professional experience findings. Through the experiential learning theory of Kolb which consists of four cycles, here I only focus on one cycle, that is concrete experience, which is matched with the experience gained by pre-service teachers. After conducting online interviews with the pre-service teachers, using thematic analysis, the findings showed that the professional experiences of pre-service teachers in Malaysia is almost the same as in Indonesia, but differ in teaching and culture. While in the challenges, pre-service teachers struggle in class and religious practice management. However, for future research, coping strategies can be included.