Relatively little data has been collected documenting the scope of family nurse practitioner (FNP) clinical practice, and virtually no research definitively describes the quality of that practice. Physicians have led the way in quantitative collection of practice content information. The resulting analyses have determined not only the most common diagnoses in primary care but also the content of teaching and research in family practice. Nurse clinicians, educators, and researchers have assumed this content to be pertinent to FNP practice as well. This article describes the major studies of family physician practice and the few studies of nurse practitioner/ FNP practice, and advocates intensified review of FNP clinical content as an empirical basis for practice, education, and research.