Objective: In this study, emotional functioning of adolescent anorexia nervosa patients was compared with two control groups; another internalizing psychiatric outpatient group and a healthy control group. Methods: Forty-eight anorexia nervosa patients (AN), 21 other psychiatric outpatients with depressive and/or anxiety disorders (PSYCH) and 48 healthy controls (HC) completed a battery of tasks and questionnaires designed to measure different aspects of emotional functioning. Cognitive (parallel) tasks were administered to control for differences of a cognitive nature. Results: The AN and the PSYCH groups had clear deficits in emotional functioning compared to the HC group. Considering the data from the alexithymia questionnaire, it was the AN group who scored significantly worse on emotional functioning when compared to the HC group. Considering the data from the emotional tasks, both psychiatric groups performed worse than the HC group in their processing of visual emotional information and the PSYCH group had more difficulty in memorizing responses to auditory emotional stimuli than the AN and HC group. Furthermore, the PSYCH group processed auditory emotional information more slowly than the HC group. No differences between the three groups were found on the non-emotional, cognitive tasks. Conclusion: Both the AN and PSYCH patients show deficits in their processing of emotional information and details are discussed.