Active learning methods have established significance in the teaching-learning of science and mathematics. This study investigated the understanding, beliefs, self-efficacy, practices, and challenges of active learning among upper primary school (grades 7 and 8) science and mathematics teachers in Ethiopia. Data were collected from 155 teachers drawn from nine schools of Addis Ababa, Amhara, and the Southern Regional States using validated questionnaires and observation. Descriptive analysis was employed to make meaning of the collected data. The result showed that teachers lack to have an appropriate understanding of active learning. But they have shown fairly consistent positive belief and self-efficacy about the outcomes of active learning if they use them in their classes. Teachers believed that they implement active learning to a higher extent. The result further indicated that teachers differ in their understanding, practices, and efficacy of active learning across their gender and educational levels. High teaching load, large class size, lack of teachers' motivation, shorter instructional time, the subject they teach, absence of guidelines for active learning methods at school, and lack of appropriate knowledge and skill of active learning methods were the common challenges reported by teachers. The findings of this study imply that there is a need to enhance teachers’ understanding of active learning and to provide continuous support to them to use active learning even in challenging situations.