Recent clinical reports have shown an increasing number of patients afflicted by eating disorders in the western world. There are numerous causes and mechanisms leading to eating disorders that affect the psychoneuroendocrinoimmune system. In this study, we define a novel psychoneuroendocrinoimmune nursing approach for anorexic and bulimic patients' treatment. According to the specific diagnostic items deriving from the Diagnostic and Statistical Manual of Mental Disorders and the International Classification of Diseases, and clinical guidelines in eating disorders formulated by the National Institute for Clinical Excellence, we carried out a qualitative study on the nursing treatment chosen by 210 international centers considered as a sample. This study was based on a no structured interview via e-mail to better understand the nursing approach in anorexia and bulimia nervosa. Thanks to the selected centers' answers, four different levels of nursing care were identified, that include: the nursing role analyzing the spectrum of patients' problems; the nursing intervention in inpatient care; the nursing intervention in outpatient care; the day hospital treatment. All four prove to be especially useful in the nursing practice.