Magnetism is a topic frequently studied in elementary schools. Since magnetism is a popular topic and is included in national science education standards, it might be assumed that elementary teachers have a good understanding of this topic and that elementary students develop a good understanding of fundamental magnetism concepts. Unfortunately, evidence suggests that magnetism concepts are poorly understood across a broad range of potential learners. The lack of successful teaching and learning of magnetism concepts that occurs at the elementary level may be partly due to deficiencies in elementary science textbooks for elementary students and elementary science methods and materials textbooks for teachers. However, ineffective science content courses in teacher preparation are likely to be a much larger problem. There is a clearly identified need to improve instruction on magnetism, and elementary science teacher education is a logical place to focus. This article reports a descriptive study of in-service elementary teachers' understanding of magnetism concepts and confidence in their understanding of those concepts before and after non-traditional instruction that utilizes instructional activities from "Physics by Inquiry." (Contains 3 tables and 5 figures.)