In this article the development of two teachers as they make the transition from pre-service teachers to experienced teachers is examined. While these teachers participated in the same mathematics methods course and similar collaborative environments in their practicum experiences, their mathematics classroom instructional practices revealed stark differences by the time they were experienced teachers. In an effort to investigate these differences, the teachers' beliefs were explored in relation to those promoted in their pre-service course and in relation to their implementation of current mathematics education reform practices. Interview Protocols are appended. (Contains 1 table and 2 figures.)