Although various governmental and professional organizations recommend that teachers use an inquiry-based approach to science education, most teachers do not use this pedagogy. Lack of content knowledge and/or insufficient skills in planning inquiry-based lessons may contribute to teachers' reluctance to utilize this methodological approach. This study explores the relationship between science content knowledge and inquiry-based lesson planning ability. The authors found a significant positive relationship between content knowledge and the ability to create an inquiry-based science lesson. These data are of great interest since proficiency in lesson-planning is believed to contribute significantly to the ability to teach an inquiry-based lesson. (Contains 1 table.)