Nurse practitioners (NPs) are at a crucial period in the development of their profession. The increasing demand for primary care practitioners is changing the environment in which they practice. As they face both increased opportunity and continuing opposition to independent practice, NPs must define their role in healthcare delivery and establish their capabilities. The debate around what is and is not an appropriate role for the NP often focuses on quality of care; however, the real issues may be turf and economic defensiveness in an increasingly competitive market. This article discusses the challenges NPs face in establishing the quality of care they provide, and it reviews the literature on the subject, identifying its strengths and weaknesses and recommending policy changes.