The term metaconceptual refers to metacognitive knowledge and processes that are acting on and related to one's conceptual system. In this study, metaconceptual teaching activities were implemented to facilitate pre-service teachers' engagement in metaconceptual processes. It was the purpose of this research to investigate the changes in pre-service teachers' alternative ideas regarding flowering plants after being exposed to metaconceptual teaching activities. The participants consisted of 32 pre-service teachers who were enrolled in a college level second-year laboratory class about flowering plants. A 13 item open-ended question set was administered a week before and a week after the instructional interventions. In order to facilitate students' engagement in metaconceptual processes, they were exposed to several instructional activities including poster drawing, journal writing, concept mapping, and class and group discussions. Alternative conceptions that pre-service teachers had prior to and following the instructional interventions were identified and the ones that changed, did not change and developed after the instruction were examined. The results of this study show that metaconceptual teaching activities were effective at changing pre-service teachers' alternative conceptions regarding flowering plants.