The current study describes the short-term outcome of adolescent inpatient population suffering from anorexia nervosa (AN) and analyzes the clinical predictors of poor outcome in these patients. Fifty-seven female AN patients (mean = 15.8, SD = 1.3) admitted for inpatient treatment to a specialized eating disorder unit at a university medical center were reassessed 1 year after being discharged. Assessments were made at the beginning and at the end of the inpatient treatment as well as at the 1-year follow-up. Self-rating data and expert-rating interview data were obtained. Adequate data for 55 (96.5%) cases allowed for the assignment of an outcome category. A total of 28.1% of the patients' cases showed a good outcome, meaning the patients fully recovered, and 8.8% had an intermediate outcome, and 59.6% of the patients' cases had a poor outcome. Significant predictors of poor outcome included the patient's BMI at the beginning of the treatment as well as psychiatric comorbidity, and purging behavior. Adolescent AN is a severe disorder with a poor outcome in a substantial amount of adolescents.