Collaboration is a widely utilized strategy for addressing complex social issues and for facilitating organizational innovation and performance. Evaluators are uniquely positioned to empirically examine the development and effects of interagency and interprofessional collaboration. In this article, the authors present the Collaboration Evaluation and Improvement Framework (CEIF), an extension of earlier work in collaboration theory development. The CEIF identifies five points of entry to evaluating collaborations and suggests actions that evaluators can take to (a) define and describe the evaluand of collaboration, (b) measure the attributes of organizational collaboration over time, and (c) increase stakeholder capacity to engage in efficient and effective collaborative practices. Use of the CEIF to operationalize and assess the construct of collaboration can enable the evaluator to ascertain how collaborative efforts correlate with indicators of organizational impact and outcomes. (Contains 1 table, 4 figures and 1 note.)