Using drama to teach science has been promoted as a fruitful teaching method yet there has been almost no theorisation and little research. This paper reports a South African study analysing lessons of four student teachers, all General Education and Training (GET) drama majors. Student teachers each used drama simulations and non-drama lessons to teach the same science concepts to similar classes of learners in grades 6 and 7. Data were collected from video transcripts of lessons using drama, researchers' field notes and student teachers' documentation supplemented by post-lesson interviews with student teachers, class teachers and groups of learners. Critical teaching episodes, identified for the four drama lessons, showed positive impact of student teachers' organisation of simulated drama but that they often failed to link scientific phenomena, concepts and processes with learners' simulated actions. Student teachers often over-directed the drama and restricted greater learner autonomy and space for open dialogic classroom discourse that might have helped embed knowledge. Implications for initial and in-service training of science teachers and future research are discussed.