This publication is an updated scope of practice statement and 16 revised standards for the clinical and administrative professional practice of ambulatory care registered nurses (RNs). The standards promote effective clinical and administrative management of increasingly complex ambulatory care RN roles and responsibilities in a changing health care environment. The scope of practice statement addresses the definition and unique characteristics of ambulatory care nursing, the conceptual framework, its history over the past 30 years, the diverse types of ambulatory care settings, the roles of ambulatory care RNs, the trends and issues in ambulatory care and future directions. The standards specify the competencies needed for professional clinical and administrative practice. Together, the scope and standards provide a structure for cataloguing and unifying the distinct nurse-patient interactions and organizational activities that occur in diverse ambulatory care environments.