OBJECTIVE: Involuntary treatment of anorexia nervosa is controversial and costly. A better understanding of the conditions that determine involuntary treatment, as well as the effect of such treatment is needed in order to adequately assess the legitimacy of this model of care. The aim of the present study was to investigate the frequency and duration of involuntary treatment, the characteristics of this group of patients, the kind of involuntary actions that are applied and the effect of such actions. REVIEW: Relevant databases were systematically searched for studies investigating the involuntary treatment of individuals diagnosed with anorexia nervosa. RESULTS: The studies included in the review contained people treated in an inpatient setting for severe or severe and enduring anorexia nervosa. People that were treated involuntarily were characterised by a more severe psychiatric load. The levels of eating disorder pathology between involuntary and voluntary groups were similar and the outcome of involuntary treatment was comparable in terms of symptom reduction to that of voluntary treatment. CONCLUSION: Despite inconsistent findings, the comparable levels of eating disorder pathology observed between involuntary and voluntary patient-groups together with findings of higher co-morbidity, more preadmissions, longer duration of illness and more incidences of self-harm for involuntary patients suggest that involuntary treatment is not a reaction to the severity of eating disorder symptoms alone, but is most likely a response to the complexity of the patient's situation as a whole.