Advanced nursing practice in the United States of America has evolved over the past decades in two related but distinct directions:- the nurse practitioner (NP) and the clinical nurse specialist (CNS). This two-role evolution was in response to social demands for increased access to affordable, quality primary health care, and at the same time to the specialised nursing care requirements of increasingly complex patients. Thus, nurse practitioners became synonymous with primary and clinical nurse specialists with specialised, acute care. There is evidence that there is an advanced practice role for both the CNS and the NP and that much of the knowledge, skills and competencies are shared depending on the clinical situation. There have been successes and failures in the development of the two roles. The clinical nurse specialists have a more respectable image among the powerful nursing education elite, but nurse practitioners are widely recognised by consumers and other health care professionals and are valued by cost-conscious managers as a viable, cheaper alternative to physicians. The literature suggests it may well be time to take the best attributes of the two roles and merge them under the term ‘advanced nurse practitioner’.