This paper reports on the use of a profiling instrument to evaluate an in-service professional development program for teachers of middle school numeracy. Two aspects of the use of the profile are reported. One relates to the aims of the profile to reflect Lee Shulman?s seven types of teacher knowledge and to measure change in teachers with respect to them. The second relates to the success of the program and how this was judged from responses to the profile. Although the providers of the program were mainly interested in this second aspect, mathematics educators more generally should be more interested in the first due to recent trends to demand evidence-based evaluations of teacher professional development programs. (Contains 2 tables.)