Ernst H, Colthorpe K. The efficacy of interactive lecturing for students with diverse science backgrounds. Adv Physiol Educ 31: 41–44, 2007; doi:10.1152/advan.00107.2006.—Learning is an active process, and, as such, interactive lectures are considered as the educational best practice. This study investigated the efficacy of interactive lecturing in a module of eight respiratory physiology lectures in a second-year Physiology course with two distinct subcohorts: students with strong science backgrounds and those without. The comparison of student performance in the summative examinations of respiratory physiology allowed us to evaluate the efficacy of interactive lecturing for each subcohort. Formal teaching evaluations were used to gauge the students’ perception of interactive lectures. To further validate our findings, we repeated the study in the following year. The introduction of interactive lecturing significantly improved learning outcomes, with this improvement being maintained for the period of this study. Furthermore, students with limited prior knowledge, who had typically performed very poorly in this module, achieved a similar learning outcome to those students with a good science background. From these summative results and the students’ perceptions, we concluded that students that are alert, motivated and interested in the subject, and engaged in learning activities and that are being encouraged to think and receive constant feedback on their progress will become confident in their learning abilities and have improved learning outcomes.