In the youngsters with chronic fatigue syndrome, we found evidence of unrealistic views of normative fatigue levels. On an 11-point visual analogue scale (0=no fatigue), and regardless of recovery status, expected adolescent normative fatigue levels were significantly lower in the subjects with chronic fatigue syndrome (median=1.2, quartiles 0.5 to 1.5) and in their parents than in healthy comparison subjects (median=4.0, quartiles 3.0 to 4.5) (p=0.001, Mann-Whitney U test). Together with the documented tendency by children with chronic fatigue syndrome and their parents to underestimate the children’s actual levels of activity, this lends some support to the presence of distorted health perceptions or expectations.