Loss of appetite that may cause weight loss is a common symptom in Major Depressive Disorder. On the other hand Anorexia Nervosa is described as restriction of energy intake leading to significantly low body weight, accompanying intense fear of gaining weight or of becoming fat. Significant weight loss that does not occur exclusively during the course of anorexia nervosa or bulimia nervosa is included in the new DSM-5. Avoidant/restrictive food intake disorder (ARFID) is a new diagnostic category in DSM-5. Although described as Feeding Disorder of Infancy or Early Childhood before, it is not restricted to childhood in DSM-5. As ARFID is categorized within Feeding and Eating Disorders in DSM-5, new researches focusing prevalence and incidence in different populations will facilitate the development of innovations for this group of patients. Here in this case report, we present a patient with significant weight loss without fear of gaining weight or becoming fat. A 33-year-old, married female patient, known to have depressive symptoms for nearly 16 years without full remission and no prior psychiatric admission or treatment. She had been lost 20 kg in the last ten months’ period, she has been 40.5 kg and BMI was 15.8 at the time of examination, was our case. She was hospitalized because of depressed mood, markedly diminished interest and pleasure, significant weight loss and suicidal ideation. During her first evaluation after hospitalization, she reported that she couldn’t eat anything, never felt hunger and eating reminds her of ‘death’. She was uncomfortable for being so thin, loosing her hair and having problems with her teeth. ‘My legs look like a child’s’ she said and reported no binge eating, provoked vomiting or excessive exercising. Her menstruations were periodic with normal duration. In her psychiatric evaluation she was depressive with suicidal ideas and plans. Her sleep pattern was evidently affected which she reported to be increased. She had marked anhedonia and hopelessness with lack of energy and concentration. She felt guiltiness because of her incapacity of household responsibilities and diminished social functioning. Besides she had no psychotic features. This case example with ARFID illustrates the importance of differential diagnosis. We also make a revision of the topic, rare in literature, in clinical features, differential diagnosis and treatment approaches, suggesting a conceptual approach for ARFID. Key research findings and core clinical features focusing on diagnosis and treatment are highlighted. The clinicians should pay attention to the eating disorders’ group that may be concealing a broader diagnosis.