Background - Only one previous randomized controlled trial (RCT) has examined the efficacy of cognitive behaviour therapy (CBT) for chronic fatigue syndrome (CFS) in children. The aim of this study was to compare family-focused CBT with psycho-education for CFS in adolescents. Method - Sixty-three 11- to 18-year-olds (43 girls, 20 boys) with CFS were randomly assigned to either family-focused CBT or psycho-education delivered over 6 months. School attendance was the main outcome, which was assessed at the end of treatment and at 3, 6 and 12 months follow-up. Results - At the main outcome point (the 6-month follow-up) both groups had improved similarly. However, although those who received family-focused CBT were attending school for longer than those who received psycho-education, at discharge from treatment and at 3 months follow-up, they improved less quickly across the follow-up period. Conclusions - Adolescents with CFS get back to school more quickly after family-focused CBT. This is important as they are at a crucial stage of their development. However, the finding that psycho-education was as effective as family-focused CBT at 6 and 12 months follow-up has important implications for health service delivery.