Little has been reported on prognostic indicators in children with chronic fatigue syndrome (CFS). We used interviews with children and parents, a mean of 45.5 months after illness onset, to follow up 25 cases of CFS referred to tertiary paediatric psychiatric clinics. At its worst, the illness had been markedly handicapping (prolonged bed-rest and school absence in two-thirds); mean time out of school was one academic year. Two-thirds, however, had recovered and resumed normal activities--mean duration of illness to recovery/assessment 38 months--and none had developed other medical conditions. Recovery was associated with specific physical triggers to the illness, with start of illness in the autumn school term and with higher socioeconomic status. Severe fatigue states in children can cause serious and longlasting handicap but most children recover.