This study explored the impact of a reflective teaching method on pre-service elementary teachers' conceptual understanding of the lunar phases, reasons for seasons, and simple electric circuits. Data were collected from 40 pre-service elementary teachers about their conceptual understanding of the lunar phases, reasons for seasons and day and night, and simple electric circuits pre and post instruction. Findings show that the instructional approach adopted by a science teacher educator had a significant impact on pre-service elementary school teachers' conceptual understanding of lunar phases, seasonal changes and simple electric circuits. The discussion focuses on pre-service elementary school teachers' misconceptions about the lunar phases, seasonal changes and simple electric circuits as revealed through their answers to the pre-test questions. Further discussion focuses on the implications of the findings for pre-service elementary school science teacher education.