This study was conducted in a reform-based mathematics and science teacher education program in the USA, the Maryland Collaborative for Teacher Preparation (MCTP). The goal of the undergraduate program was to prepare upper elementary/middle level specialists in mathematics and science. One significant aspect of the MCTP was the expectation that the program's professors (in mathematics and science) would model a new vision of effective pedagogy based on reform-based recommendations. We determined, in general, that the program's mathematics and science content professors accepted the dual role of modeling effective instruction at the same time they were delivering content. However, this dual responsibility raised in their minds an "issue of appropriate balance" between content and pedagogical foci in their courses. Previously, the professors' had not questioned a focus heavily tilted toward content coverage. We also determined that the program's teacher candidates believed that the mathematics and science professors modeled effective instruction. One of the primary reasons that the teacher candidates believed that their professors were modeling effective instruction was that the focus in the courses was primarily on conceptual understanding, not memorization. A major implication was that the professors' modeling of reform-based instruction prompted the teacher candidates to develop a new vision of mathematics and science teaching shaped by their professors' example.