This study investigates the effectiveness of the Discovery Learning model assisted by multimedia in enhancing students’ learning outcomes on the topic of the respiratory system at SMA Negeri Bunga Bangsa, Nagan Raya Regency. Employing an experimental method with a one-group pretest–posttest design, the research involved 29 students from class XI-B, selected through purposive sampling. Learning outcomes were assessed using pre-test and post-test instruments. The results demonstrated a substantial improvement in student performance, with the mean score increasing from 48,44 in the pre-test to 85,69 in the post-test. All participants achieved scores above the Minimum Mastery Criteria (80). These findings suggest that incorporating multimedia into Discovery Learning effectively facilitates the comprehension of abstract biological concepts, particularly in respiratory system material. The study concludes that the integration of interactive multimedia within Discovery Learning not only supports conceptual understanding but also enhances student engagement and achievement. It is recommended that educators adopt this approach as a pedagogical strategy in biology education to optimize learning outcomes.