This article describes an interactive professional development unit that engages both novice and experienced evaluators in (a) learning about the Essential Competencies for Program Evaluators (ECPE), (b) applying the competencies to program evaluation contexts, and (c) using the ECPE to reflect on their own professional practices. The article briefly summarizes current issues about program evaluator competencies and the components of effective professional development. It then describes the ECPE; the objectives, content, and process of the professional development session; and the ECPE Self-Assessment Instrument. Facilitators can adapt and use the unit in a variety of settings, including university courses and program evaluation conferences. (Contains 1 note, 2 tables, and 2 figures.)