Objective Our aims were to investigate the relationship between food addiction and mental disorders including eating disorders (ED), eating‐related psychopathology and body mass index‐standard deviation score in a sample of adolescent psychiatric inpatients. Methods Food addiction was assessed with the Yale Food Addiction Scale (YFAS). Eating‐related psychopathology was measured with the Three‐Factor Eating Questionnaire (TFEQ). Psychiatric diagnoses were assessed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. The sample consisted of n = 242 adolescent psychiatric inpatients, of which n = 37 (15.3%) met criteria for an ED. Multiple regression analysis was used to examine the association between YFAS symptom count, TFEQ scales and ED controlling for age and gender. Results Food addiction frequency was 16.5%, and the mean YFAS symptom count was 2.39 (SD: 1.60). In patients with food addiction, TFEQ scale scores were significantly higher than patients without food addiction. Frequency of ED was 42.9% in patients with and 9.9% in patients without food addiction. The TFEQ subscales disinhibition and hunger as well as diagnosis of ED were associated with YFAS symptom count. Discussion Food addiction in adolescent psychiatric inpatients occurs with rates higher than those seen in community samples of children, adolescents and adults. Food addiction might be associated with eating styles related to susceptibility to hunger and feelings of loss of control. The implications of high‐YFAS scores in restricting‐type anorexia nervosa warrant further investigations to explore which and how the respective items are interpreted in this ED subgroup. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.