OBJECTIVE: The course and clinical predictors of rehospitalization were studied in a large sample of adolescent patients with anorexia nervosa who had been treated at five European sites and been followed-up. METHOD: Two-hundred and twelve adolescent patients first admitted for in-patient treatment, aged 10-18 (Mean 14.9) years and 94.8% female, were followed-up for an average of 8.3 years after first admission at sites in (former East and West Berlin, Zurich, Sofia, and Bucharest). Clinical history data were collected by use of standardized item-sheets at first admission. Semi-structured interviews including ratings of eating pathology and psychosocial outcome were performed at follow-up. RESULTS: About 44.8% (95/212) of the patients required at least one readmission. Rates of rehospitalization were significantly higher at the Eastern sites (Sofia and Bucharest). Significant predictors of readmission were paternal alcoholism, history of anorexia nervosa in the family, eating disorder in infancy, periodic overactivity, lower weight increase at first admission, and lower BMI at first discharge. In a model of logistic regression analysis, five variables (paternal alcoholism, eating disorder in infancy, periodic overactivity, low weight increase during first admission, and low BMI at first discharge) correctly classified 69% of the participants into cases with single or repeated admissions. Patients with repeated admissions had a less favorable long term outcome and had higher rates of persisting psychopathology at follow-up. CONCLUSION: Rehospitalization reflects the chronic course in a sizable proportion of adolescent patients with anorexia nervosa. Family psychopathology may have an effect both in terms of genetic vulnerability and environmental stress leading to unfavorable courses. The strong effect of insufficient weight gain during first admission and lower BMI at first discharge emphasizes the importance of adequate interventions. Readmissions carry the risk for later poor psychosocial and psychiatric outcomes.