RESUMEN
The prevalence of chronic fatigue syndrome (CFS) in teenagers is 10-20 per 100,000 inhabitants in the Netherlands. The natural course of the disorder is not favourable according to the literature. Proposed criteria for the diagnosis 'CFS' in adolescence are: absence of a physical explanation for the complaints, a disabling fatigue for at least six months and prolonged school absenteeism or severe motor and social disabilities. Exclusion criterion should be a psychiatric disorder. Factors that attribute to the persistence of fatigue are somatic attributions, illness enhancing cognitions and behaviour of parents as well as physical inactivity. The role of the physician and the role of parents can enhance the problems. The treatment should focus on decreasing the somatic attributions, on reinforcement by the parents of healthy adolescent behaviour, on the gradual increase of physical activity and on decreasing attention (including medical attention) for the somatic complaints.