This study investigates the experiences of English as a Foreign Language (EFL) learners from UIN Ar-Raniry Banda Aceh who participated in the International Community Service Program (PPKPM) in Thailand, focusing on the challenges of culture shock and the adaptation strategies employed during their teaching practice. Using a qualitative case study approach, data were collected through in-depth interviews with eight participants were purposively selected from the 2021 cohort of the English Education Department at UIN Ar-Raniry to explore their perceptions, challenges, and coping mechanisms in a cross-cultural teaching context. The findings reveal that participants encountered significant cultural challenges, including language barriers, differences in classroom management styles, adaptation to local customs, and varying levels of student engagement. Emotional impacts such as homesickness, confusion, and feelings of isolation were also evident during the initial adjustment phase. Despite these challenges, participants employed various adaptation strategies such as learning basic Thai phrases, using translation tools, observing and imitating local practices, and relying on peer and community support. These strategies not only facilitated smoother integration into the host environment but also enhanced participants’ intercultural competence and teaching skills. The study underscores the importance of cultural awareness and flexibility in international teaching programs and suggests that future participants be provided with pre-departure cultural training to better prepare them for the challenges of teaching abroad.