Objective: To analyse in a systematic way the concept of denial of illness in anorexia nervosa, especially (part 2) with regard to its various forms and meanings. Method: A detailed review of the available literature on the subject. Results: Two major categories of denial can be distinguished. First, there is unintentional denial including all sorts of distorted information processing. It may be a sign of neurobiologically impaired self-awareness (anosognosia), a psychotic-like reality distortion, a dissociative phenomenon, or a coping mechanism with various meanings. We will discuss the most important theoretical approaches (cognitive, psychodynamic and interpersonal) to understand unintentional denial. The second category can be described as deliberate denial or refusal of self-disclosure (including 'faking good'), expressing an avoidance of feared consequences or a need of self-determination. Discussion: The complexity of denial is not reflected in the available research and clinicians underestimate its interactional significance with respect to the patients' social surrounding, including the health care system.