This study examines the role of Islamic Religious Education teachers and parents in shaping the religious behavior of tenth-grade students at MA Al-Islam Surakarta in the 2025/2026 academic year. The objective of this research is to explore how educational guidance at school and parental involvement at home contribute to the development of students’ religious conduct. This study employed a qualitative research approach using a descriptive case study design. The participants consisted of 30 tenth-grade students selected purposively, along with Islamic Religious Education teachers and several parents as supporting informants. Data were collected through in-depth interviews, participant observation, and documentation, and were analyzed using data reduction, data display, and conclusion drawing techniques. The findings reveal that the synergy between teachers and parents plays a significant role in strengthening students’ religious behavior. Approximately 83% of students demonstrated consistent daily prayer practices, 76% showed active participation in religious school activities, 70% reflected respectful attitudes toward teachers and parents, and 68% exhibited internalization of Islamic moral values in social interactions. The results indicate that structured religious instruction at school combined with parental supervision and modeling at home substantially contributes to the formation of students’ religious character. Therefore, collaborative engagement between educational institutions and families is essential in fostering sustainable religious behavior among adolescents