This study explores parental involvement in the modular learning of high school students, focusing on challenges faced, teacher interventions, and the perceived benefits of teacher-parent mentoring. Through in-depth interviews with 80 parents and 5 teachers, the qualitative research uncovers challenges in content mastery, learning environments, material organization, and progress monitoring. Teachers respond with interventions such as workshops, home visitations, and resource provisions. The study reveals that parents struggle with understanding complex subjects, limited learning spaces, and organizing materials. Teachers' interventions include training sessions, home visits, and supplementary materials to address these challenges. Additionally, the research highlights the positive impact of teacher-parent mentoring on scholastic success. Recommendations include continuous training for parents, home visitation programs, resource provisions, progress monitoring support, and institutional backing for mentorship initiatives. These insights contribute to educational practices, guiding the development of effective support systems for high school learners in modular learning environments, emphasizing the importance of collaborative efforts between teachers and parents.