The call for evidence has swept the healthcare landscape in medicine and nursing and more recently in nursing management. Nurse managers and administrators have been identified as important to support research use and evidence-based practice. The primary focus of this article is (1) to describe the concept of evidence, (2) to challenge the wisdom of basing the practice of leadership on a narrow (reductionistic) understanding of the concept of evidence, and (3) to argue for a rethinking on what should count as evidence in nursing administration. Semantic analysis and examination of dictionaries reveal that evidence as a concept has both an internal and an external dimension. To understand the concept of evidence in a profound sense as well as its significance for leadership this article describes 3 different meanings of the concept: ontological, contextual, and King's evidence.