This overview article introduces the topic of capacity and capacity development (CD), noting the vagueness and multiplicity of definitions and approaches. It presents the model of capacity developed by the European Centre for Development Policy Management (ECDPM) study, and reviews our evolving understanding of CD. Brief summaries of the contributions to the symposium highlight the main findings and key points. The contents of the symposium include four country cases—Pakistan, Tanzania, Brazil, and Papua New Guinea (PNG)—and one conceptual piece on CD in fragile states. Several common themes emerge: the benefits of viewing capacity and CD through systems lenses, the salience of the politics of CD; and the need to change how donors and capacity builders approach the practice of CD. Copyright © 2010 John Wiley & Sons, Ltd.