In order to reach students who can efficiently use intended scientific understandings, it is important to have science teachers without conceptual difficulties. The aim of present research is to enhance pre-service science teachers' conceptual understanding about boiling by dialogic teaching. The sample consisted of forty-three pre-service science teachers in their first year of teacher education. Dialog-based instructional activities were conducted in a chemistry laboratory course. Audio recordings of classroom discourse and written texts were used for data collection. Pre-service science teachers' conceptions about boiling identified before and after dialogic teaching were analyzed using content analysis. The findings showed that dialogic teaching efficiently supported pre-service science teachers' understanding about boiling.