Middle school teachers have been encouraged to view themselves as lifelong learners engaged in a collaborative process of improving their teaching practices and content knowledge. In this article, the authors describe how to use actual events, or dilemmas, for case-based discussions in order to facilitate the professional development of middle school teachers. The authors begin by describing cases and the important role they can play in the professional development of middle school teachers. They also discuss guidelines for using dilemmas to write cases and share them with colleagues. In addition, the authors present a dilemma involving plagiarism by a middle school student and describe how it can be used to promote professional development. (Contains 4 figures.)