The health crisis has accentuated the teaching-learning challenges in the national school system, highlighting the urgency of improving educational quality. To achieve this, it is essential to improve pedagogical practices in classrooms, moving from conventional methods to student-centered strategies. This allows active and conscious participation in their challenges and achievements, adapting to current needs. This research analyzes the beliefs of secondary school teachers in Chile through a multiple case study in three high schools in the Metropolitan Region. The opportunities and difficulties linked to active learning in high schools that apply a teacher professional development program were explored. The results reveal that teachers incorporate their beliefs about active learning, considering factors such as the diversity of students, the development of skills such as inquiry and reflection, and the challenges that come with the transition from a traditional to an active approach. These findings indicate that teachers are willing to adopt active learning, demonstrating a commitment to improvement, which increases the challenge for the educational system to provide the necessary tools to make this possible.