ABSTRACT. Objective. To examine psychosocial problems and adaptation of adolescent girls with chronic fatigue syndrome (CFS).Methodology. Thirty-six adolescent girls with CFS (mean age: 15.2 years; mean syndrome duration: 19.7 months) who fulfilled the criteria of the Centers for Disease Control and Prevention were examined by interviews regarding premorbid problems and by questionnaires regarding psychosocial functioning and distress, psychological attitudes, and coping resources. Data were compared with normative data.Results. Of the adolescents, 86.1% reported 1 or more premorbid problems (58.3% physical, 38.9% psychological, and 52.8% familial). Normal adjustment was reported for psychosocial self-esteem, social abilities, and attentional abilities. High adjustment to adult social standards of behavior was found, but low perceived competence in specific adolescent domains, such as athletic ability, romance, and participation in recreational activities. The girls reported predominantly internalizing problems. Normal achievement motivation, no debilitating fear of failure, and high internal locus of control were observed. Palliative reaction patterns and optimism were predominantly used as coping strategies.Conclusions. The large number of premorbid problems suggests a possible contributing factor to the onset of the syndrome, although there were no reference data of healthy adolescents. In distinct domains of psychosocial adjustment, the adolescent girls with CFS showed strengths such as adequate self-esteem and scholastic and social abilities, and weaknesses such as low competence in adolescent-specific tasks and internalizing distress, which may partly be explained by syndrome-specific somatic complaints. The use of optimistic and palliative reaction patterns as coping strategies in this patient group indicates that the patients with CFS seem to retain an active and positive outlook on life, which may result in a rather adequate psychological adaptation to the syndrome, but also in maintenance of the syndrome by exceeding the physical limits brought about by the CFS. Our results on adjustment and coping strategies may be helpful to implement (individual) rehabilitation programs. Pediatrics 2001;107(3). URL: http://www. pediatrics.org/cgi/content/full/107/3/e35; chronic fatigue syndrome, adolescents, female, psychological adjustment, coping behavior.