Anorexia nervosa is an extremely serious psychiatric illness that appears during adolescence. This illness is an eating disorder and mainly affects young women who, according to studies, account for nine out of 10 sufferers. It is characterized by the following three symptoms (DSM-5, 2013): (i) a calorie-restrictive diet in relation to the physiological needs of the individual which leads to rapid and massive weight loss, (ii) an intense fear of weight gain, even when extremely low weight has been reached, and (iii) distorted self body representation, in particular an exaggeration of weight and body shape. The patients see themselves as bigger than they actually are. This symptom is extremely important, as it is likely to counteract the effects of therapy, as the patient never reaches their “ideal” weight. In addition, according to researchers, dissatisfaction with body shape could be a precursor to the illness. Many researchers in genetics, neurobiology and psychology have attempted to gain better understanding of this pathology in order to find efficient treatment or therapy. It is clear that, although many treatments and therapies now exist, their effectiveness is still very limited, even for cognitive and behavioral therapy. However, the situation is urgent as anorexia nervosa can lead to death through malnutrition but also suicide. This pathology has the highest suicide rate of all psychiatric disorders. Thus, it would seem important to undertake further research to gain better understanding of this pathology. The aim of this review is to see how studies in the field of cognitive neuropsychology can contribute to improving the care and treatment of patients. With regard to intellectual ability, studies lack consensus and it is necessary to carry out wider experiments with larger control groups. However, it would seem that patients, once they reach a very low weight, perform less well in classic intelligent tests, affecting all sub-scores. This result could be connected to the decrease in the volume of grey matter that has been evidenced. Fortunately, patients seem to show improved performances once they have regained weight. Like personality studies that have shown that certain characteristics such as perfectionism, asceticism and fear of maturity are linked to this illness, data from cognitive neuropsychology seems to highlight certain specific components. Perceptive organization, mental flexibility, short-term memory and central coherence are all components that appear to be particularly affected by anorexia nervosa. Adapted and individualized cognitive therapy could be offered to improve the affected components, such as weak cognitive flexibility that can be an obstacle to change the behavior. In addition, studies on the exaggeration of body shape and weight (frequent complaints of patients) show that this illusion does not only concern conscious, emotional and aesthetic body image, but is also linked to a more basic, sensory-motor representation: the body schema. The parietal cortex seems to be involved in this disorder of body schema. Self-awareness about the body is a key element in the success of the renutrition process. The therapies should focus on the body with real contact (via massage for instance) and with the help of virtual reality. This could enhance the re-appropriation of the new limits of the emaciated body and could permit also to more accept the actual and future enlarged body during the renutrition process. Finally, experimental paradigms from cognitive psychology that explore non-classical functions such as multi-sensorial integration and the use of brain imaging techniques should lead to better understanding of the underlying neural systems. This information could be added to existing knowledge about anorexia nervosa in order to refine therapies offered and to improve the individual treatment of these patients experiencing deep psychic and physical pain.