Understanding how the knowledge structures of preservice teachers develop as expertise is acquired would seem to be an important aspect of teacher preparation. The purpose of this study was to compare the pedagogical knowledge structures about effective teaching of preservice teachers and teacher educators in the professional preparation programs of two different institutions. Two groups of preservice teachers at two different points in their preparation program at each of the two institutions were asked to complete a concept map (Roehler et al., 1987) about effective teaching. One group completed the concept map just after the first teaching methods course, and the other group completed the map just prior to student teaching. These data were compared with concept maps of teacher educators at each institution. Quantitative and qualitative data revealed differences between the groups of preservice teachers and between the preservice teachers and the teacher educators.