The authors present the argument that evaluation as currently practiced is failing the needs of the social sector, if the goal is to help organizations achieve their mission. Three case studies are presented in which evaluation played a key role in the development of a learning culture within the organization. Each case highlights the positive potential for evaluation to foster continuous organizational learning and improvement, build relationships, and facilitate organizational development. The authors find that although capacity building efforts by funders were important, the commitment of organizational leadership was critical in transforming the role of evaluation from one of basic reporting and accountability to a true process of continuous organizational learning. This transformation requires leadership commitment to development of an evaluative learning culture and an infrastructure to support it. (Contains 1 table and 2 notes.)